IVOAT Thesaurus - Version Thu Jul 3 16:30:01 2008
type: ConceptScheme
has top concept: DopplerEffect
has top concept: FourierTransform
has top concept: JulianDate
has top concept: KapteynSelectedArea
has top concept: NewtonianTelescope
has top concept: XRaySpectrum
has top concept: absorption
has top concept: abundance
has top concept: activeRegion
has top concept: almanac
has top concept: analysis
has top concept: anomaly
has top concept: arc
has top concept: array
has top concept: artificialSatellite
has top concept: astronomicalResearch
has top concept: astronomicalTechnique
has top concept: atlas
has top concept: atmosphere
has top concept: atmosphericRadiation
has top concept: binarySystem
has top concept: blueObject
has top concept: bubble
has top concept: bulge
has top concept: burst
has top concept: calendar
has top concept: calibration
has top concept: catalog
has top concept: chemicalElement
has top concept: chemicalEvolution
has top concept: classification
has top concept: cloud
has top concept: cluster
has top concept: coating
has top concept: coherence
has top concept: collapse
has top concept: collisionProcess
has top concept: compactObject
has top concept: computer
has top concept: computing
has top concept: constant
has top concept: controlSystem
has top concept: coordinateSystem
has top concept: corona
has top concept: correlation
has top concept: crater
has top concept: density
has top concept: design
has top concept: detection
has top concept: diffraction
has top concept: dimension
has top concept: dipole
has top concept: disk
has top concept: distanceMeasurement
has top concept: distanceScale
has top concept: eclipse
has top concept: electrode
has top concept: electrodynamics
has top concept: electromagneticTheory
has top concept: electronBeam
has top concept: electronicCamera
has top concept: electronicEquipment
has top concept: emissionLineObject
has top concept: encounter
has top concept: energy
has top concept: energyTransfer
has top concept: epoch
has top concept: equinox
has top concept: error
has top concept: evolution
has top concept: evolutionaryTrack
has top concept: extragalacticObject
has top concept: eyepiece
has top concept: filter
has top concept: fission
has top concept: flare
has top concept: flow
has top concept: fluorescence

21CmLine
type: Concept
alt label: 21 cm line
broader: radioRecombinationLine
definition: 21 centimeter line of hydrogen
pref label: 21-cm line
related: HI
related: HIAbsorption
related: HICloud
related: HIContent
related: HIEmission
related: HIRegion
related: hydrogen
related: radioFrequency

53PerseiStar
type: Concept
broader: BStar
broader: pulsatingVariableStar
definition: 53 Persei star
pref label: 53 Persei star

AbellCluster
type: Concept
broader: galaxyCluster
definition: Abell cluster
pref label: Abell cluster

aberration
type: Concept
definition: aberration of light
pref label: aberration
related: astrometry
related: coordinateSystem

ablation
type: Concept
definition: ablation
pref label: ablation
related: meteorite

abnormalSpectrum
type: Concept
broader: spectrum
definition: abnormal spectrum
pref label: abnormal spectrum
related: peculiarStar

absoluteMagnitude
type: Concept
broader: magnitude
definition: absolute magnitude
pref label: absolute magnitude
related: HertzsprungRussellDiagram
related: WilsonBappuEffect
related: distance
related: distanceModulus
related: luminosity

absoluteTemperatureScale
type: Concept
broader: temperatureScale
definition: absolute temperature scale
narrower: Kelvin
pref label: absolute temperature scale
related: celsiusTemperatureScale
related: temperature
scope note: ES: moved Kelvin from RT to NT (2007-OCT-8)

absorption
type: Concept
definition: absorption
narrower: atmosphericExtinction
narrower: intergalacticAbsorption
narrower: interstellarAbsorption
narrower: lightAbsorption
pref label: absorption
related: RosselandOpacity
related: atmosphericScattering
related: atmosphericWindow
related: capture
related: equivalentWidth
related: interstellarGas
related: opacity
related: photodissociation
related: photoionization
related: radiation
related: radiativeEquilibrium
related: reddenedStar
related: reddening
related: transmission
scope note: combine with other terms

absorptionCoefficient
type: Concept
alt label: absorptivity
definition: absorption coefficient
pref label: absorption coefficient
related: EinsteinCoefficient
related: atmosphericExtinction
related: intergalacticAbsorption
related: interstellarAbsorption
related: opticalDepth
related: transparency

absorptionLine
type: Concept
broader: spectralLine
definition: absorption line
narrower: absorptionLineSystem
pref label: absorption line
related: LymanAlphaForest
related: VoigtProfile
related: atomicProcess
related: boundFreeTransition
related: calciumLine
related: cyanogenLine
related: lineFormation
related: lineIdentification
related: lineProfile
related: lineRatio
related: metalLine
related: microturbulence
related: residualIntensity
related: spectroscopicAnalysis
related: spectrum

absorptionLineSystem
type: Concept
broader: absorptionLine
broader: system
definition: absorption line system
history note: ES: new (2007-OCT-8)
pref label: absorption line system
related: quasar

absorptionSpectroscopy
type: Concept
broader: spectroscopy
definition: absorption spectroscopy
pref label: absorption spectroscopy

absorptionSpectrum
type: Concept
broader: lineSpectrum
broader: spectrum
definition: absorption spectrum
narrower: atomicSpectrum
pref label: absorption spectrum
related: BalmerSeries
related: DLine
related: FraunhoferLine
related: RamanEffect
related: boundFreeTransition
related: energySpectrum

abundance
type: Concept
alt label: chemical abundance
alt label: element abundance
alt label: stellar abundance
definition: abundance
narrower: cosmicAbundance
narrower: isotopicAbundance
narrower: metalAbundance
narrower: overabundance
narrower: underabundance
pref label: abundance
related: CnoAnomaly
related: abundanceRatio
related: chemicalComposition
related: chemicalElement
related: chemicalEvolution
related: curveOfGrowth
related: elementFormation
related: enrichment
related: heavyElement
related: heliumPoorStar
related: heliumRichStar
related: peculiarStar
related: rareEarth
scope note: may be combined with element, e.g. helium abundance

abundanceRatio
type: Concept
definition: abundance ratio
pref label: abundance ratio
related: CnoAnomaly
related: abundance

acceleration
type: Concept
broader: kinematics
definition: acceleration
pref label: acceleration
related: deceleration
related: gravimetry
related: orbit
related: orbitalElement

accretion
type: Concept
definition: accretion
pref label: accretion
related: AlfvenSurface
related: accretionDisk
related: binaryStar
related: massTransfer
related: particleAccretion

accretionDisk
type: Concept
broader: disk
definition: accretion discs UK
definition: accretion disk
pref label: accretion disk
related: accretion
related: blackHole
related: circumstellarDisk
related: closeBinaryStar
related: coolingFlow
related: dwarfNova
related: lowMassXRayBinaryStar
related: stellarWind
related: superhump

achondrite
type: Concept
broader: chondrite
broader: meteorite
definition: achondrite
pref label: achondrite

acoustics
type: Concept
definition: acoustics
pref label: acoustics
related: acousticWave

acousticWave
type: Concept
alt label: sound
alt label: sound wave
broader: wave
definition: acoustic wave
pref label: acoustic wave
related: acoustics
related: gravityWave
related: soundSpeed
related: wavelength

actinium
type: Concept
alt label: Ac
broader: fundamentalChemicalElement
definition: actinium (atomic number 89)
history note: FVH: new (2007-OCT-25)
pref label: actinium

activeGalacticNucleus
type: Concept
alt label: AGN
broader: XRaySource
broader: galacticNucleus
broader: variableSource
definition: active galactic nucleus
narrower: SeyfertNucleus
narrower: blazar
pref label: active galactic nucleus
related: BlLacertaeObject
related: activeGalaxy
related: compactNucleus
related: emissionLineGalaxy
related: galaxy
related: quasar
related: radioGalaxy

activeGalaxy
type: Concept
alt label: eruptive galaxy
broader: XRaySource
broader: galaxy
definition: active galaxy
pref label: active galaxy
related: XRayFlare
related: activeGalacticNucleus
related: compactGalaxy
related: emissionLineGalaxy

activeOptics
type: Concept
broader: optics
definition: active optics
pref label: active optics
related: adaptiveOptics
related: atmosphericRefraction
related: multipleMirrorTelescope
related: seeing
related: tipTiltMirror

activeProminence
type: Concept
broader: activeRegion
broader: prominence
definition: active prominence
pref label: active prominence
related: Sun

activeRegion
type: Concept
definition: solar active region
history note: FVH: new (2007-OCT-29)
narrower: activeProminence
pref label: active region
related: Sun

activeStar
type: Concept
broader: star
definition: active star
narrower: XRayStar
narrower: emissionLineStar
pref label: active star
related: XRayFlare

activeSun
type: Concept
broader: Sun
definition: active Sun
pref label: active Sun
related: flare
related: quietSun
related: solarActivity
related: solarCycle
related: sunspot

activityIndex
type: Concept
definition: activity index
pref label: activity index
related: solarActivity

adaption
type: Concept
definition: adaption
pref label: adaption
scope note: combine with other terms

adaptiveOptics
type: Concept
broader: optics
definition: adaptive optics
pref label: adaptive optics
related: activeOptics
related: atmosphericRefraction
related: seeing
related: segmentedOptics

adiabaticProcess
type: Concept
definition: adiabatic process
pref label: adiabatic process
related: energyTransfer
related: thermodynamics

adjustment
type: Concept
definition: adjustment
pref label: adjustment
related: alignmentOptics
related: collimation
related: correction
related: optics
related: orientation
scope note: combine with other terms

adsorption
type: Concept
definition: adsorption
pref label: adsorption
related: dustGrain
related: interplanetaryGrain
related: interstellarDust
scope note: combine with other terms

ADwarf
type: Concept
broader: AStar
broader: dwarf
definition: A dwarf star
pref label: A dwarf
related: ASubdwarf

aerolite
type: Concept
broader: meteorite
definition: aerolite
pref label: aerolite

aeronomy
type: Concept
broader: scientificField
definition: aeronomy
pref label: aeronomy
related: EarthAtmosphere
related: atmosphere
related: planet

AeStar
type: Concept
broader: AStar
broader: HerbigAeBeStar
broader: earlyTypeEmissionStar
definition: Ae star
narrower: HerbigAeBeStar
pref label: Ae star
related: BeStar

afterglow
type: Concept
broader: atmosphericRadiation
definition: afterglow
pref label: afterglow
related: lightScattering
related: luminescence

age
type: Concept
definition: age
pref label: age
related: HubbleTime
related: cosmochronology
related: relaxationTime
related: turnoffPoint
scope note: combine with other terms

AGiant
type: Concept
broader: AStar
broader: giant
definition: A giant star
pref label: A giant

air
type: Concept
broader: gas
definition: air
pref label: air
related: atmosphere

airConditioning
type: Concept
definition: air conditioning
pref label: air conditioning
related: temperatureControl
related: ventilation

airglow
type: Concept
alt label: dayglow
alt label: nightglow
broader: atmosphericRadiation
definition: airglow
pref label: airglow
related: RayleighScattering
related: ashenLight
related: aurora
related: nightSkyBrightness
related: radiativeRecombination
related: skyBrightness

airplaneBorneInstrument
type: Concept
alt label: airplane borne instrument
broader: instrument
definition: airplane-borne instrument
pref label: airplane-borne instrument
related: balloonBorneInstrument
related: groundBasedAstronomy
related: infraredObservatory
related: rocketBorneInstrument
related: satelliteBorneInstrument

airPollution
type: Concept
broader: pollution
definition: air pollution
pref label: air pollution
related: lightPollution
related: siteProtection

AiryDisk
type: Concept
definition: Airy discs UK
definition: Airy disk
pref label: Airy disk
related: diffraction

albedo
type: Concept
alt label: spherical albedo
broader: opticalProperty
definition: albedo
pref label: albedo
related: illumination
related: radiation
related: reflection
related: surfaceProperty

AlfvenSurface
type: Concept
definition: Alfven surface
pref label: Alfven surface
related: accretion
related: neutronStar

AlfvenWave
type: Concept
alt label: hydromagnetic wave
broader: magnetohydrodynamics
definition: Alfven wave
narrower: coronalWave
pref label: Alfven wave

AlgolVariableStar
type: Concept
alt label: beta Persei star
broader: binaryStar
broader: eclipsingBinaryStar
definition: Algol variable star
pref label: Algol variable star
related: WUrsaeMajorisStar

alignmentOptics
type: Concept
definition: alignment of optical image
pref label: alignment optics
related: adjustment
related: collimation
related: correction
related: orientation

allSkyCamera
type: Concept
alt label: all sky camera
broader: camera
broader: wideFieldTelescope
change note: FVH: added NT CLOUD_MONITORS (2007-SEP-21)
definition: all-sky camera
narrower: cloudMonitor
pref label: all-sky camera
related: allSkyPhotography
related: wideAngleLens

allSkyPhotography
type: Concept
alt label: all sky photography
broader: photography
definition: all-sky photography
pref label: all-sky photography
related: allSkyCamera
related: camera
related: wideAngleLens

almanac
type: Concept
definition: almanac
narrower: nauticalAlmanac
pref label: almanac
related: ephemeris

alpha2CanumVenaticorumStar
type: Concept
broader: eruptiveBinaryStar
broader: magneticVariableStar
change note: FVH: removed incorrect BT cataclysmic_variable_star (2007-OCT-2)
definition: alpha2 Canum Venaticorum star
pref label: alpha2 Canum Venaticorum star
related: ApStar
related: SxArietisStar
related: spectrumVariableStar

alphaParticle
type: Concept
broader: boson
broader: compositeParticle
broader: nuclearRadiation
broader: particle
definition: alpha particle
pref label: alpha particle
related: electron
related: neutron
related: proton
related: radioactivity

altazimuthMounting
type: Concept
alt label: alt-azimuth mounting
alt label: azimuth mounting
broader: telescopeMounting
definition: altazimuth mounting
pref label: altazimuth mounting
related: altitudeAngle
related: azimuth
related: equatorialMounting
related: horizonCoordinateSystem
related: siderostat
related: verticalCircle

altimeter
type: Concept
broader: measuringInstrument
definition: altimeter
pref label: altimeter
related: weatherStation

altimetry
type: Concept
definition: altimetry
pref label: altimetry

altitudeAngle
type: Concept
alt label: elevation angle
definition: altitude [angle]
pref label: altitude angle
related: altazimuthMounting
related: azimuth
related: horizon
related: horizonCoordinateSystem
related: sextant
related: zenithDistance
scope note: use for angle; see ALTITUDE_HEIGHT for height

aluminizing
type: Concept
definition: aluminizing
pref label: aluminizing
related: aluminumCoating
related: mirror
related: vacuumTechnique

aluminum
type: Concept
alt label: Al
broader: fundamentalChemicalElement
definition: aluminum (atomic number 13)
history note: FVH: new (2007-OCT-25)
narrower: aluminumCoating
pref label: aluminum

aluminumCoating
type: Concept
broader: aluminum
broader: coating
broader: thinFilm
change note: FVH: moved aluminium_coating to localized D (2007-SEP-24)
definition: aluminium coating UK
definition: aluminum coating
pref label: aluminum coating
related: aluminizing
related: mirror
related: opticalSurface
related: silverCoating
related: vacuumTechnique
related: vaporDeposition

amateurAstronomy
type: Concept
broader: astronomy
definition: amateur astronomy
pref label: amateur astronomy
related: astronomer
related: astronomicalResearch

AmCanumVenaticorumStar
type: Concept
broader: hydrogenDeficientStar
broader: novaLikeVariable
definition: AM Canum Venaticorum star
pref label: AM Canum Venaticorum star
related: UxUrsaeMajorisStar
related: dwarfNova

americium
type: Concept
alt label: Am
broader: fundamentalChemicalElement
definition: americium (atomic number 95)
history note: FVH: new (2007-OCT-25)
pref label: americium

AmHerculisStar
type: Concept
alt label: polars
broader: cataclysmicVariableStar
definition: AM Herculis star
pref label: AM Herculis star

ammonia
type: Concept
broader: interstellarMolecule
definition: ammonia
pref label: ammonia

AmorGroup
type: Concept
broader: minorPlanetFamily
definition: Amor group
pref label: Amor group
related: ApolloGroup
related: TrojanGroup

amplifier
type: Concept
broader: instrument
definition: amplifier
narrower: microchannelPlate
narrower: parametricAmplifier
narrower: preamplifier
pref label: amplifier
related: imageTube
related: photomultiplierTube
related: pulseCounter
related: pulseCounting

amplitude
type: Concept
definition: amplitude
pref label: amplitude
related: decayOscillation
related: magnitude
related: oscillation
related: pulsation
related: variableStar
related: vibration

AmStar
type: Concept
broader: AStar
broader: magneticStar
broader: magneticVariableStar
broader: metalRichStar
definition: Am star
narrower: spectrumVariableStar
pref label: Am star

analogRecorder
type: Concept
broader: dataStorage
definition: analog recorder
pref label: analog recorder

analysis
type: Concept
definition: analysis
narrower: dataAnalysis
narrower: fineAnalysis
narrower: signalAnalysis
narrower: signalProcessing
pref label: analysis
related: astronomicalTechnique
related: quantization
related: reductionMethod
scope note: combine with other terms

anemometer
type: Concept
broader: measuringInstrument
definition: anemometer
history note: FVH: new (2007-SEP-21)
pref label: anemometer
related: weatherStation
related: windVane

angularDiameter
type: Concept
alt label: apparent diameter
broader: diameter
definition: angular diameter
narrower: isophotalDiameter
pref label: angular diameter
related: interferometry
related: occultation
related: speckleInterferometry

angularMomentum
type: Concept
definition: angular momentum
pref label: angular momentum
related: kinematics
related: momentum
related: rotation

angularResolution
type: Concept
broader: resolution
definition: angular resolution
pref label: angular resolution
related: angularSeparation
related: beamwidth
related: optics
related: speckleInterferometry

angularSeparation
type: Concept
alt label: angular distance
definition: angular separation
pref label: angular separation
related: angularResolution
related: opticalDoubleStar
related: speckleInterferometry

angularVelocity
type: Concept
broader: velocity
definition: angular velocity
pref label: angular velocity
related: celestialMechanics
related: orbitalVelocity
related: rotation

anisotropy
type: Concept
definition: anisotropy
pref label: anisotropy
related: backgroundRadiation
related: isotropy
related: polarizationChargeSeparation

annualEquation
type: Concept
definition: annual equation
pref label: annual equation
related: EarthMoonSystem
related: EarthOrbit
related: ellipticalOrbit

annualParallax
type: Concept
alt label: heliocentric parallax
alt label: parallax
broader: parallax
definition: annual parallax
pref label: annual parallax
related: AstronomicalUnit

annularEclipse
type: Concept
broader: eclipse
definition: annular eclipse
pref label: annular eclipse
related: totalEclipse

anomalisticMonth
type: Concept
definition: anomalistic month
pref label: anomalistic month
related: Moon
related: orbitalAnomaly

anomalisticYear
type: Concept
broader: year
definition: anomalistic year
pref label: anomalistic year
related: orbitalAnomaly

anomaly
type: Concept
change note: FVH: generic non-orbital anomaly; old entry moved to orbital_anomaly (2007-OCT-29)
definition: anomaly
narrower: CnoAnomaly
narrower: gravityAnomaly
narrower: magneticAnomaly
pref label: anomaly

ansa
type: Concept
definition: ansa
pref label: ansa
related: lenticularGalaxy
related: planetaryNebula
related: ring

antapex
type: Concept
definition: antapex
pref label: antapex
related: apex
related: solarMotion

antarcticObservatory
type: Concept
broader: observatory
definition: antarctic observatory
pref label: antarctic observatory

antenna
type: Concept
alt label: aerials
alt label: antennas
broader: radarEquipment
definition: antenna
narrower: CassegrainAntenna
narrower: MillsCrossAntenna
narrower: YagiAntenna
narrower: dipoleAntenna
narrower: directionalAntenna
narrower: hornAntenna
narrower: lensAntenna
narrower: microwaveAntenna
narrower: parabolicAntenna
narrower: radioAntenna
narrower: reflectorAntenna
pref label: antenna
related: array
related: current
related: currentSheet
related: dishAntenna
related: feedHorn
related: interferometer
related: radar
related: radioTelescope
related: telescope

antennaDesign
type: Concept
definition: antenna design
pref label: antenna design
related: polarDiagram
related: radioTelescope

anthropicPrinciple
type: Concept
definition: anthropic principle
pref label: anthropic principle
related: cosmology
related: life

antimatter
type: Concept
broader: matter
definition: antimatter
narrower: antiparticle
pref label: antimatter

antimony
type: Concept
alt label: Sb
broader: fundamentalChemicalElement
definition: antimony (atomic number 51)
history note: FVH: new (2007-OCT-25)
pref label: antimony

antineutrino
type: Concept
broader: antiparticle
definition: antineutrino
pref label: antineutrino
related: neutrino

antinode
type: Concept
definition: antinode
pref label: antinode
related: vibration

antinucleon
type: Concept
broader: antiparticle
definition: antinucleon
pref label: antinucleon

antiparticle
type: Concept
broader: antimatter
broader: elementaryParticle
definition: antiparticle
narrower: antineutrino
narrower: antinucleon
narrower: antiproton
narrower: positron
pref label: antiparticle

antiproton
type: Concept
broader: antiparticle
definition: antiproton
pref label: antiproton
related: proton

antireflectionCoating
type: Concept
broader: coating
broader: opticalFilm
broader: thinFilm
definition: antireflection coating
pref label: antireflection coating
related: lens
related: opticalSurface

apastron
type: Concept
broader: apsis
definition: apastron
pref label: apastron
related: periastron

aperiodicComet
type: Concept
broader: comet
definition: aperiodic comet
pref label: aperiodic comet

aperture
type: Concept
definition: aperture
pref label: aperture
related: apertureSynthesis
related: apodization
related: opticalSystem

apertureSynthesis
type: Concept
alt label: synthetic aperture
definition: aperture synthesis
pref label: aperture synthesis
related: aperture
related: gradingFunction
related: gratingRing
related: interferometry
related: visibilityFunction

apex
type: Concept
definition: apex
pref label: apex
related: antapex
related: solarMotion

aphelion
type: Concept
broader: apsis
definition: aphelion
pref label: aphelion
related: EarthOrbit
related: perihelion
related: planet

apocenter
type: Concept
definition: apocenter
pref label: apocenter
related: binaryStar

apodization
type: Concept
alt label: apodisation UK
definition: apodization
pref label: apodization
related: aperture
related: radioTelescope

apogee
type: Concept
broader: apsis
definition: apogee
pref label: apogee
related: Moon
related: perigee

ApolloGroup
type: Concept
broader: minorPlanetFamily
definition: Apollo group
pref label: Apollo group
related: AmorGroup
related: HirayamaFamily
related: TrojanGroup

apparentIntensity
type: Concept
broader: intensity
definition: apparent intensity
pref label: apparent intensity

apparentMagnitude
type: Concept
broader: magnitude
definition: apparent magnitude
narrower: BMagnitude
narrower: HMagnitude
narrower: IMagnitude
narrower: JMagnitude
narrower: KMagnitude
narrower: LMagnitude
narrower: MMagnitude
narrower: NMagnitude
narrower: OMagnitude
narrower: PMagnitude
narrower: QMagnitude
narrower: RMagnitude
narrower: UMagnitude
narrower: VMagnitude
narrower: photoelectricMagnitude
narrower: photographicMagnitude
narrower: photovisualMagnitude
pref label: apparent magnitude
related: photometricSystem
related: photometry

apparentPosition
type: Concept
alt label: apparent places
broader: position
definition: apparent position
pref label: apparent position
related: astrometry
related: truePosition

apparentSuperluminalMotion
type: Concept
alt label: superluminal motion
broader: motion
definition: apparent superluminal motion
pref label: apparent superluminal motion
related: velocityOfLight

apsidalMotion
type: Concept
broader: motion
definition: apsidal motion
pref label: apsidal motion
related: apsis
related: orbit

apsis
type: Concept
alt label: apse
broader: orbitalElement
definition: apsis
narrower: apastron
narrower: aphelion
narrower: apogee
narrower: periastron
narrower: perigee
narrower: perihelion
pref label: apsis
related: apsidalMotion
related: orbit
scope note: apse = apsis, apsides is plural

ApStar
type: Concept
alt label: peculiar A star
broader: AStar
broader: peculiarStar
definition: Ap star
narrower: holmiumStar
narrower: manganeseStar
narrower: siliconStar
narrower: spectrumVariableStar
pref label: Ap star
related: alpha2CanumVenaticorumStar
related: magneticStar
related: magneticVariableStar
related: obliqueRotator
related: rapidOscillation

arc
type: Concept
change note: FVH: made general term (2007-OCT-1)
definition: arc
narrower: auroralArc
narrower: luminousArc
pref label: arc

archaeoastronomy
type: Concept
alt label: ancient astronomy
alt label: astroarchaeology
broader: astronomy
broader: historyOfAstronomy
definition: archaeoastronomy
narrower: megalithicAstronomy
pref label: archaeoastronomy
related: armillarySphere
related: astrolabe
related: astrology

argon
type: Concept
alt label: Ar
broader: fundamentalChemicalElement
definition: argon (atomic number 18)
history note: FVH: new (2007-OCT-25)
pref label: argon

armillarySphere
type: Concept
broader: instrument
definition: armillary sphere
pref label: armillary sphere
related: archaeoastronomy

array
type: Concept
definition: array
narrower: detectorArray
narrower: diodeArray
narrower: phasedArray
narrower: tArray
narrower: telescopeArray
narrower: veryLongBaselineInterferometer
narrower: yArray
pref label: array
related: antenna
related: gratingResponse
related: interferometer
related: radioInterferometer
related: radioTelescope

arrayProcessor
type: Concept
broader: computer
definition: array processor
pref label: array processor
related: detectorArray

arsenic
type: Concept
alt label: As
broader: fundamentalChemicalElement
definition: arsenic (atomic number 33)
history note: FVH: new (2007-OCT-25)
pref label: arsenic

artificialSatellite
type: Concept
definition: artificial satellite
narrower: geostationarySatellite
narrower: spaceObservatory
pref label: artificial satellite
related: polarOrbit
related: satelliteLaserRanging
related: spaceAstronomy
related: spaceTelescope
related: spaceVehicle

ascendingNode
type: Concept
broader: node
change note: FVH: moved NODES to BT (2007-OCT-1)
definition: ascending node
pref label: ascending node

ashenLight
type: Concept
broader: atmosphericRadiation
definition: ashen light
pref label: ashen light
related: Venus
related: airglow
scope note: refers to Venus' atmosphere

AStar
type: Concept
broader: earlyTypeStar
definition: A star
narrower: ADwarf
narrower: AGiant
narrower: ASubdwarf
narrower: ASubgiant
narrower: ASupergiant
narrower: AeStar
narrower: AmStar
narrower: ApStar
pref label: A star
related: earlyTypeVariableStar
related: spectralType

astatine
type: Concept
alt label: At
broader: fundamentalChemicalElement
definition: astatine (atomic number 85)
history note: FVH: new (2007-OCT-25)
pref label: astatine

asteroid
type: Concept
alt label: minor planet
alt label: planetoid
broader: rotatingBody
definition: asteroid
narrower: nearEarthAsteroid
pref label: asteroid
related: EdgeworthKuiperBelt
related: KirkwoodGap
related: SolarSystem
related: asteroidBelt
related: asteroidOccultation
related: interplanetaryMatter
related: meteorStream
related: meteorite
related: meteoroid
related: meteoroidDustCloud
related: minorPlanetFamily
related: planetesimal
related: resonanceGap
related: transNeptunianObject

asteroidBelt
type: Concept
definition: asteroid belt
pref label: asteroid belt
related: asteroid

asteroidOccultation
type: Concept
broader: occultation
definition: occultation by asteroid
history note: FVH: new (2007-OCT-8)
pref label: asteroid occultation
related: asteroid

asteroseismology
type: Concept
alt label: stellar seismology
broader: seismology
definition: asteroseismology
narrower: helioseismology
pref label: asteroseismology
related: pulsatingVariableStar
related: pulsation
related: rapidOscillation
related: solarOscillation
related: stellarOscillation

astigmatism
type: Concept
broader: opticalAberration
definition: astigmatism
pref label: astigmatism
related: chromaticAberration
related: comaticAberration
related: distortion
related: fieldCurvature
related: sphericalAberration

astrobiology
type: Concept
alt label: exobiology
broader: astronomy
broader: biology
broader: scientificField
definition: astrobiology
pref label: astrobiology
related: cosmochemistry
related: extraterrestrialLife

astrodynamics
type: Concept
definition: astrodynamics
pref label: astrodynamics
related: celestialMechanics

astrograph
type: Concept
broader: astrometricInstrument
definition: astrograph
pref label: astrograph

astrographicCamera
type: Concept
broader: camera
definition: astrographic camera
pref label: astrographic camera

astrographicCatalog
type: Concept
alt label: astrographic catalogues UK
broader: catalog
definition: astrographic catalog
pref label: astrographic catalog

astrolabe
type: Concept
broader: astrometricInstrument
broader: instrument
definition: astrolabe
narrower: DanjonAstrolabe
narrower: impersonalAstrolabe
pref label: astrolabe
related: archaeoastronomy

astrology
type: Concept
broader: scientificField
definition: astrology
pref label: astrology
related: archaeoastronomy
related: astronomy
related: constellation
related: planet
related: zodiac

astrometricBinaryStar
type: Concept
broader: binaryStar
definition: astrometric binary star
pref label: astrometric binary star

astrometricInstrument
type: Concept
broader: instrument
definition: astrometric instrument
narrower: astrograph
narrower: astrolabe
narrower: quadrant
narrower: sextant
narrower: transitInstrument
pref label: astrometric instrument
related: astrometry
related: time

astrometry
type: Concept
alt label: positional astronomy
broader: astronomicalTechnique
broader: astronomy
broader: observingTechnique
definition: astrometry
narrower: photographicAstrometry
narrower: radioAstrometry
narrower: spaceAstrometry
pref label: astrometry
related: EarthRotation
related: aberration
related: apparentPosition
related: astrometricInstrument
related: astronomicalGeodesy
related: celestialMechanics
related: coordinateSystem
related: equatorPosition
related: fundamentalStar
related: latitudeDetermination
related: meridianCircle
related: opticalPosition
related: parallax
related: precession
related: referenceSystem
related: stellarMotion
related: transit
related: transitInstrument
related: truePosition

astronomer
type: Concept
definition: astronomer
pref label: astronomer
related: amateurAstronomy
related: astronomicalResearch

astronomicalConstant
type: Concept
broader: constant
definition: astronomical constant
narrower: AstronomicalUnit
narrower: OortConstant
pref label: astronomical constant
related: celestialMechanics
related: physicalConstant

astronomicalGeodesy
type: Concept
broader: geodesy
definition: astronomical geodesy
pref label: astronomical geodesy
related: astrometry

astronomicalOptics
type: Concept
broader: optics
definition: astronomical optics
pref label: astronomical optics

astronomicalResearch
type: Concept
definition: astronomical research
narrower: spaceResearch
pref label: astronomical research
related: amateurAstronomy
related: astronomer

astronomicalTechnique
type: Concept
definition: astronomical technique
narrower: astrometry
narrower: interferometry
narrower: photometry
narrower: polarimetry
narrower: spectrophotometry
narrower: spectroscopy
pref label: astronomical technique
related: analysis
related: observingTechnique
related: photography
related: reductionMethod
scope note: most used in several wavelength region

AstronomicalUnit
type: Concept
alt label: A.U.
alt label: AU
broader: astronomicalConstant
change note: FVH: added ALT A.U. (2007-09-21)
definition: Astronomical Unit
pref label: Astronomical Unit
related: annualParallax
related: distanceScale
related: heliocentricCorrection
related: parallax
related: parsec
related: solarParallax
related: trigonometricParallax

astronomy
type: Concept
broader: scientificField
definition: astronomy
narrower: amateurAstronomy
narrower: archaeoastronomy
narrower: astrobiology
narrower: astrometry
narrower: cosmicRayAstronomy
narrower: cosmogony
narrower: cosmology
narrower: groundBasedAstronomy
narrower: infraredAstronomy
narrower: spaceAstronomy
pref label: astronomy
related: astrology

astrophysics
type: Concept
broader: scientificField
change note: FVH: moved theoretical_astrophysics to NT (2007-OCT-1)
definition: astrophysics
narrower: highEnergyAstrophysics
narrower: theoreticalAstrophysics
pref label: astrophysics
related: cosmology
scope note: combine with other terms

ASubdwarf
type: Concept
broader: AStar
broader: subdwarf
definition: A subdwarf star
pref label: A subdwarf
related: ADwarf

ASubgiant
type: Concept
broader: AStar
broader: subgiant
definition: A subgiant star
pref label: A subgiant

ASupergiant
type: Concept
broader: AStar
broader: earlyTypeSupergiant
broader: supergiant
definition: A supergiant star
pref label: A supergiant

asymptoticGiantBranch
type: Concept
alt label: AGB
definition: asymptotic giant branch
pref label: asymptotic giant branch
related: HertzsprungRussellDiagram
related: lateTypeGiant
related: postAsymptoticGiantBranch

ataxite
type: Concept
broader: meteorite
definition: ataxite
pref label: ataxite

atlas
type: Concept
alt label: chart
definition: atlas
narrower: starAtlas
pref label: atlas
related: catalog
related: findingChart
related: map
related: skySurvey
related: survey

atmosphere
type: Concept
definition: atmosphere
narrower: EarthAtmosphere
narrower: stellarAtmosphere
pref label: atmosphere
related: aeronomy
related: air
related: boundaryLayer
related: greenhouseEffect
related: limbBrightening
related: limbDarkening
related: macroturbulence
related: microturbulence
related: opacity
related: planet
related: radiationBelt
related: refractionAngle
related: scaleHeight
related: scintillation
related: temperatureZone
related: waterVapor
scope note: combine with other terms

atmosphericDensity
type: Concept
broader: density
definition: atmospheric density
pref label: atmospheric density
related: scaleHeight

atmosphericExtinction
type: Concept
alt label: extinction
broader: absorption
broader: scattering
definition: atmospheric extinction
pref label: atmospheric extinction
related: EarthAtmosphere
related: absorptionCoefficient
related: atmosphericWindow
related: lightAbsorption
related: lightScattering
related: ultravioletExtinction
scope note: refers to Earth atmosphere

atmosphericRadiation
type: Concept
alt label: sky radiation
definition: atmospheric radiation
narrower: afterglow
narrower: airglow
narrower: ashenLight
narrower: aurora
narrower: terrestrialRadiation
pref label: atmospheric radiation
related: skyBrightness
scope note: ES: moved terrestrial_radiation from BT to NT (2007-OCT-8)

atmosphericRefraction
type: Concept
definition: atmospheric refraction
pref label: atmospheric refraction
related: activeOptics
related: adaptiveOptics
related: atmosphericScintillation
related: pointSpreadFunction
related: refractiveIndex
related: scintillation
related: seeing
related: speckle

atmosphericScattering
type: Concept
definition: atmospheric scattering
pref label: atmospheric scattering
related: EarthAtmosphere
related: absorption

atmosphericScintillation
type: Concept
alt label: twinkling
broader: scintillation
definition: atmospheric scintillation
pref label: atmospheric scintillation
related: EarthAtmosphere
related: atmosphericRefraction
related: seeing

atmosphericTide
type: Concept
broader: tide
definition: atmospheric tide
pref label: atmospheric tide

atmosphericWindow
type: Concept
broader: window
definition: atmospheric window
narrower: infraredTransmissionWindow
narrower: opticalTransmissionWindow
narrower: radioTransmissionWindow
pref label: atmospheric window
related: EarthAtmosphere
related: absorption
related: atmosphericExtinction
related: transparency
scope note: spectral ranges transmitted by the Earth's atmosphere

atom
type: Concept
broader: matter
definition: atom
narrower: fundamentalChemicalElement
pref label: atom
related: chemicalElement

atomicClock
type: Concept
alt label: caesium clock
alt label: cesium clock
broader: clock
broader: measuringInstrument
definition: atomic clock
pref label: atomic clock
related: atomicTime
related: geodesy
related: time
related: timeStandard
related: timeSynchronization
related: veryLongBaselineInterferometry

atomicLine
type: Concept
definition: atomic line
pref label: atomic line
related: atomicSpectrum

atomicPhysics
type: Concept
broader: scientificField
definition: atomic physics
pref label: atomic physics

atomicProcess
type: Concept
definition: atomic process
pref label: atomic process
related: absorptionLine
related: emissionLine
related: equationOfState
related: excitation
related: populationInversion

atomicSpectrum
type: Concept
broader: absorptionSpectrum
broader: spectrum
definition: atomic spectrum
pref label: atomic spectrum
related: atomicLine

atomicTime
type: Concept
definition: atomic time
pref label: atomic time
related: atomicClock

attenuation
type: Concept
definition: attenuation
pref label: attenuation
related: filter
related: neutralDensityFilter

aurora
type: Concept
broader: atmosphericRadiation
definition: aurora
narrower: auroralArc
narrower: auroralJet
pref label: aurora
related: Rayleigh
related: airglow
related: lightEmission
related: magneticDisturbances
related: magneticPole
related: magneticStorm
related: nightSkyBrightness
related: photoionization
related: skyBrightness
related: solarActivity
related: upperAtmosphere

auroralArc
type: Concept
broader: arc
broader: aurora
definition: auroral arc
pref label: auroral arc

auroralJet
type: Concept
broader: aurora
definition: auroral jet
pref label: auroral jet

australite
type: Concept
broader: meteorite
broader: tektite
definition: australite
pref label: australite
related: bediasite
related: chondrite
related: moldavite

autoCorrelation
type: Concept
alt label: autocorrelation
broader: correlation
definition: auto-correlation
history note: FVH: new (2007-NOV-1)
pref label: auto-correlation
related: crossCorrelation
related: dataProcessing

autoguider
type: Concept
broader: controlSystem
broader: guideSystem
definition: autoguider
pref label: autoguider
related: automaticPatrolTelescope
related: quadrantDetector
related: tracking

automatedTelescope
type: Concept
alt label: robotic telescope
broader: telescope
definition: automated telescope
narrower: automaticPatrolTelescope
pref label: automated telescope
related: remoteControlSystem

automaticPatrolTelescope
type: Concept
broader: automatedTelescope
broader: opticalTelescope
definition: automatic patrol telescope
pref label: automatic patrol telescope
related: autoguider
related: photometry
related: remoteControlSystem

autumnalEquinox
type: Concept
broader: equinox
definition: autumnal equinox
pref label: autumnal equinox
related: vernalEquinox

auxiliaryInstrument
type: Concept
broader: instrument
definition: auxiliary instrument
pref label: auxiliary instrument

avalanchePhotodiode
type: Concept
broader: photodiode
broader: photoelectronicDevice
definition: avalanche photodiode
pref label: avalanche photodiode
related: photometry

axialRatio
type: Concept
broader: ratio
definition: axial ratio
history note: ES: new (2007-OCT-11)
pref label: axial ratio
related: axis
related: majorAxis
related: minorAxis

axion
type: Concept
broader: elementaryParticle
definition: axion
pref label: axion

axis
type: Concept
definition: axis
pref label: axis
related: axialRatio
scope note: combine with other terms

azimuth
type: Concept
alt label: bearing
definition: azimuth
pref label: azimuth
related: altazimuthMounting
related: altitudeAngle
related: horizon
related: horizonCoordinateSystem

BaadeWesselinkMethod
type: Concept
definition: Baade-Wesselink method
pref label: Baade-Wesselink method
related: Cepheid
related: diameter

background
type: Concept
definition: background
pref label: background
scope note: combine with other terms

backgroundNoise
type: Concept
broader: noise
definition: background noise
pref label: background noise
related: cosmicNoise
related: signalToNoiseRatio
related: skyNoise

backgroundRadiation
type: Concept
alt label: radiation background
broader: radiation
definition: background radiation
narrower: XRayBackground
narrower: cosmicBackgroundRadiation
narrower: cosmicRay
narrower: gammaRayBackground
narrower: microwaveBackground
narrower: radioBackground
narrower: ultravioletBackground
pref label: background radiation
related: SunyaevZeldovichEffect
related: anisotropy
related: cosmicNoise
related: skyBrightness

BaileyType
type: Concept
alt label: AB variable star
broader: RrLyraeStar
definition: Bailey type
pref label: Bailey type

bailysBead
type: Concept
definition: Baily's bead
pref label: bailys bead
related: Sun
related: diamondRingEffect
related: solarEclipse

BakerNunnCamera
type: Concept
broader: catadioptricSystem
broader: meteorCamera
broader: reflectingTelescope
broader: wideFieldTelescope
definition: Baker-Nunn camera
pref label: Baker-Nunn camera
related: BouwersTelescope
related: SchmidtTelescope

balloonBorneInstrument
type: Concept
alt label: balloon borne instrument
definition: balloon-borne instrument
pref label: balloon-borne instrument
related: XRayAstronomy
related: airplaneBorneInstrument
related: cosmicRayAstronomy
related: gammaRayAstronomy
related: groundBasedAstronomy
related: rocketBorneInstrument
related: satelliteBorneInstrument
related: spaceProbeInstrument
related: spaceTelescope
related: ultravioletAstronomy

BalmerContinuum
type: Concept
broader: hydrogenSpectrum
definition: Balmer continuum
pref label: Balmer continuum
related: BalmerSeries

BalmerLimit
type: Concept
broader: BalmerSeries
definition: Balmer limit
pref label: Balmer limit

BalmerSeries
type: Concept
alt label: Balmer line
broader: hydrogenSpectrum
definition: Balmer series
narrower: BalmerLimit
narrower: HAlpha
narrower: HBeta
narrower: HDelta
narrower: HEpsilon
narrower: HGamma
pref label: Balmer series
related: BalmerContinuum
related: BrackettSeries
related: LymanSeries
related: PaschenSeries
related: PfundSeries
related: absorptionSpectrum

barium
type: Concept
alt label: Ba
broader: fundamentalChemicalElement
definition: barium (atomic number 56)
history note: FVH: new (2007-OCT-25)
pref label: barium
related: bariumStar

bariumStar
type: Concept
alt label: Ba II star
broader: star
definition: barium star
narrower: semiBariumStar
pref label: barium star
related: SStar
related: barium
related: heavyMetalStar

barometer
type: Concept
broader: measuringInstrument
definition: barometer
history note: FVH: new (2007-SEP-21)
pref label: barometer
related: pressure
related: weatherStation

barredSpiralGalaxy
type: Concept
broader: galaxy
broader: spiralGalaxy
definition: barred spiral galaxy
narrower: BGalaxy
pref label: barred spiral galaxy

baryon
type: Concept
broader: elementaryParticle
definition: baryon
pref label: baryon
related: OmegaBaryon
related: quark

baryonicDarkMatter
type: Concept
broader: DarkMatter
definition: baryonic Dark Matter
pref label: baryonic Dark Matter
related: coldDarkMatter

basin
type: Concept
definition: basin
pref label: basin
related: crater

BBand
type: Concept
broader: FraunhoferLine
broader: molecularBand
definition: B band
pref label: B band
related: molecularSpectrum

BDwarf
type: Concept
broader: BStar
broader: dwarf
definition: B dwarf star
narrower: gammaCassiopeiaeStar
pref label: B dwarf

beamSwitching
type: Concept
definition: beam switching
pref label: beam switching
related: radioTelescope

beamWaveguide
type: Concept
definition: beam waveguide
pref label: beam waveguide
related: collimator

beamwidth
type: Concept
definition: beamwidth
pref label: beamwidth
related: angularResolution
related: polarDiagram
related: radioTelescope

bediasite
type: Concept
broader: meteorite
broader: tektite
definition: bediasite
pref label: bediasite
related: australite
related: chondrite
related: moldavite

berkelium
type: Concept
alt label: Bk
broader: fundamentalChemicalElement
definition: berkelium (atomic number 97)
history note: FVH: new (2007-OCT-25)
pref label: berkelium

beryllium
type: Concept
alt label: Be
broader: fundamentalChemicalElement
definition: beryllium (atomic number 4)
history note: FVH: new (2007-OCT-25)
pref label: beryllium

BesselianEpoch
type: Concept
broader: epoch
broader: standardEpoch
definition: Besselian epoch
pref label: Besselian epoch
related: JulianEpoch
related: time

BesselPhotometry
type: Concept
alt label: Bessel UBVRI photometry
broader: broadBandPhotometry
broader: photometricSystem
definition: Bessel photometry
history note: FVH: new (2007-SEP-21)
pref label: Bessel photometry
related: BMagnitude
related: BvPhotometry
related: IMagnitude
related: JohnsonPhotometry
related: RMagnitude
related: UMagnitude
related: VMagnitude

BeStar
type: Concept
alt label: Be dwarf star
broader: BStar
broader: HerbigAeBeStar
broader: earlyTypeEmissionStar
change note: FVH: moved Be_dwarf to ALT and U Herbig_star to BT HERBIG_AeBe_STARS (2007-OCT-1)
definition: Be star
narrower: HerbigAeBeStar
narrower: lambdaEridaniStar
pref label: Be star
related: AeStar
related: circumstellarShell

betaCepheiStar
type: Concept
alt label: beta Canis Majoris star
broader: earlyTypeVariableStar
broader: multiPeriodicVariableStar
broader: pulsatingVariableStar
broader: shortPeriodVariableStar
definition: beta Cephei star
pref label: beta Cephei star
related: nonRadialPulsation
related: radialPulsation

betaLyraeStar
type: Concept
broader: closeBinaryStar
broader: contactBinaryStar
broader: eclipsingBinaryStar
broader: ellipsoidalVariableStar
definition: beta Lyrae star
pref label: beta Lyrae star

BGalaxy
type: Concept
broader: barredSpiralGalaxy
definition: barred galaxy (Yerkes classification scheme)
history note: FVH+AG: new (2007-OCT-26)
pref label: B galaxy
related: YerkesClassification

BGiant
type: Concept
broader: BStar
broader: giant
definition: B giant star
pref label: B giant

BianchiCosmology
type: Concept
broader: cosmology
definition: Bianchi cosmology
pref label: Bianchi cosmology

biasCalibration
type: Concept
broader: calibration
definition: bias calibration
history note: FVH: new (2007-OCT-3)
pref label: bias calibration
related: CcdDetector

BigBangTheory
type: Concept
broader: cosmology
definition: Big Bang theory
pref label: Big Bang theory
related: FriedmannUniverse
related: HubbleRadius
related: HubbleTime
related: LemaitreUniverse
related: closedUniverse
related: earlyUniverse
related: hadronBarrier
related: openUniverse
related: primordialFireball
related: relativisticVelocity
related: steadyStateTheory

binaryPulsar
type: Concept
broader: pulsar
definition: binary pulsar
pref label: binary pulsar

binaryStar
type: Concept
alt label: binaries
alt label: double star
broader: binarySystem
broader: star
definition: binary star
narrower: AlgolVariableStar
narrower: RsCanumVenaticorumStar
narrower: astrometricBinaryStar
narrower: closeBinaryStar
narrower: contactBinaryStar
narrower: detachedBinaryStar
narrower: eclipsingBinaryStar
narrower: ellipsoidalVariableStar
narrower: eruptiveBinaryStar
narrower: interactingBinaryStar
narrower: semiDetachedBinaryStar
narrower: spectroscopicBinaryStar
narrower: visualBinaryStar
narrower: wideBinaryStar
pref label: binary star
related: accretion
related: apocenter
related: centerOfMass
related: companionStar
related: dynamicalParallax
related: inclination
related: massLoss
related: massRatio
related: multipleStar
related: occultation
related: orbit
related: orbitDetermination
related: period
related: periodChange
related: periodDetermination
related: phaseWave
related: positionAngle
related: runawayStar
related: semimajorAxis
related: separation
related: twoBodyProblem
related: vonZeipelTheorem
scope note: only the broad classes are shown below; specific type will be found under these, or from the hierarchical list

binarySystem
type: Concept
definition: binary system
narrower: binaryStar
narrower: doubleGalaxy
pref label: binary system

biology
type: Concept
broader: scientificField
definition: biology
narrower: astrobiology
narrower: spaceBiology
pref label: biology

bipolarGalaxy
type: Concept
broader: galaxy
definition: bipolar galaxy
pref label: bipolar galaxy

bipolarGroup
type: Concept
broader: sunspotGroup
definition: bipolar group
pref label: bipolar group
related: sunspot

bipolarNebula
type: Concept
broader: nebula
definition: bipolar nebula
pref label: bipolar nebula
related: bipolarOutflow

bipolarOutflow
type: Concept
alt label: bipolar flow
broader: massLoss
definition: bipolar outflow
pref label: bipolar outflow
related: bipolarNebula
related: circumstellarMatter
related: radioSource
related: radioStructure

birthRate
type: Concept
definition: birth rate
pref label: birth rate
related: massFunction
related: protostar
related: starFormation
related: stellarEvolution

bismuth
type: Concept
alt label: Bi
broader: fundamentalChemicalElement
definition: bismuth (atomic number 83)
history note: FVH: new (2007-OCT-25)
pref label: bismuth

blackBodyRadiation
type: Concept
alt label: thermal black body radiation
broader: electromagneticRadiation
definition: black body radiation
pref label: black body radiation
related: brightnessTemperature
related: emissivity
related: thermalRadiation
related: ultravioletRadiation

blackDwarf
type: Concept
broader: dwarf
broader: lowMassStar
broader: stellarObject
definition: black dwarf star
pref label: black dwarf
related: whiteDwarf

blackHole
type: Concept
broader: collapsedStar
broader: compactObject
broader: degenerateMatter
broader: relativisticStar
definition: black hole
narrower: KerrBlackHole
narrower: stellarBlackHole
pref label: black hole
related: HawkingRadiation
related: KruskalDiagram
related: PenroseProcess
related: SchwarzschildRadius
related: XRayBinaryStar
related: accretionDisk
related: ergosphere
related: eventHorizon
related: galacticNucleus
related: gravitationalCollapse
related: gravitationalLensing
related: massiveObject
related: nakedSingularity
related: relativisticAstrophysics
related: spaceTimeSingularity
related: supernovaRemnant
related: whiteHole

blankField
type: Concept
definition: blank field
pref label: blank field
related: galaxyVoid

blazar
type: Concept
broader: activeGalacticNucleus
definition: blazar
pref label: blazar
related: BlLacertaeObject
related: quasar

BlazhkoEffect
type: Concept
definition: Blazhko effect
pref label: Blazhko effect
related: RrLyraeStar

BlHerculisStar
type: Concept
broader: WVirginisStar
broader: pulsatingVariableStar
definition: BL Herculis star
pref label: BL Herculis star
related: Cepheid
related: RrLyraeStar
related: radialPulsation

blinkComparator
type: Concept
broader: instrument
definition: blink comparator
pref label: blink comparator

blinking
type: Concept
definition: blinking
pref label: blinking
scope note: combine with other terms

BlLacertaeObject
type: Concept
alt label: BL Lac object
broader: compactObject
broader: extragalacticRadioSource
broader: galaxy
broader: variableSource
definition: BL Lacertae object
pref label: BL Lacertae object
related: SeyfertGalaxy
related: activeGalacticNucleus
related: blazar
related: compactGalaxy
related: quasar

blueGalaxy
type: Concept
broader: blueObject
broader: galaxy
definition: blue galaxy
pref label: blue galaxy

blueLoop
type: Concept
broader: giantBranch
definition: blue loop
history note: ES: new (2007-OCT-8)
pref label: blue loop

blueObject
type: Concept
definition: blue object
narrower: blueGalaxy
pref label: blue object

blueshift
type: Concept
alt label: blue shift
alt label: blue-shift
broader: DopplerEffect
broader: lineShift
definition: blueshift
pref label: blueshift
related: frequencyShift

blueStragglerStar
type: Concept
broader: mainSequenceStar
broader: youngStar
definition: blue straggler star
pref label: blue straggler star
related: openStarCluster

BMagnitude
type: Concept
broader: apparentMagnitude
definition: B magnitude
pref label: B magnitude
related: BesselPhotometry
related: JohnsonPhotometry

BodesLaw
type: Concept
alt label: Titius-Bode law
definition: Bode's law
pref label: Bodes law
related: SolarSystem
related: distance
related: planet

bohrium
type: Concept
alt label: Bh
broader: fundamentalChemicalElement
definition: bohrium (atomic number 107)
history note: FVH: new (2007-OCT-25)
pref label: bohrium

BokGlobule
type: Concept
broader: darkNebula
broader: globule
broader: interstellarMatter
definition: Bok globule
pref label: Bok globule
related: HIiRegion
related: cometaryGlobule
related: protostar
related: starFormation

bolide
type: Concept
broader: meteor
definition: bolide
pref label: bolide
related: fireball

bolometer
type: Concept
broader: instrument
definition: bolometer
pref label: bolometer
related: bolometricCorrection
related: photometer
related: radiation
related: radiometer

bolometricCorrection
type: Concept
definition: bolometric correction
pref label: bolometric correction
related: bolometer

boron
type: Concept
alt label: B
broader: fundamentalChemicalElement
definition: boron (atomic number 5)
history note: FVH: new (2007-OCT-25)
pref label: boron

BoseEinsteinNucleus
type: Concept
broader: nucleusAtom
definition: Bose-Einstein nucleus
pref label: Bose-Einstein nucleus
related: BoseEinsteinStatistics
related: FermiDiracNucleus

BoseEinsteinStatistics
type: Concept
definition: Bose-Einstein statistics
pref label: Bose-Einstein statistics
related: BoseEinsteinNucleus
related: FermiDiracStatistics
related: boson

boson
type: Concept
broader: elementaryParticle
broader: particle
definition: boson
narrower: alphaParticle
narrower: compositeParticle
narrower: meson
narrower: photon
narrower: pion
pref label: boson
related: BoseEinsteinStatistics
related: fermion
related: hadron
related: lepton

boundaryLayer
type: Concept
definition: boundary layer
pref label: boundary layer
related: atmosphere
related: planet

boundFreeTransition
type: Concept
alt label: bound free transition
definition: bound-free transition
pref label: bound-free transition
related: absorptionLine
related: absorptionSpectrum

BouwersTelescope
type: Concept
broader: catadioptricSystem
broader: reflectingTelescope
definition: Bouwers telescope
pref label: Bouwers telescope
related: BakerNunnCamera
related: MaksutovTelescope
related: wideFieldTelescope

bowShock
type: Concept
broader: shockWave
definition: bow-shock
pref label: bow shock

BpStar
type: Concept
broader: BStar
broader: magneticStar
broader: peculiarStar
definition: Bp star
pref label: Bp star

BrackettSeries
type: Concept
broader: hydrogenSpectrum
broader: infraredRadiation
definition: Brackett series
pref label: Brackett series
related: BalmerSeries
related: LymanSeries
related: PaschenSeries
related: PfundSeries

bremsstrahlung
type: Concept
alt label: free free transition
alt label: free-free transition
broader: electromagneticRadiation
definition: bremsstrahlung
pref label: bremsstrahlung
related: electron
related: radiationMechanism
related: spectrum
related: synchrotronRadiation

bridge
type: Concept
definition: bridge
pref label: bridge
scope note: between galaxy

brightGalaxy
type: Concept
broader: galaxy
definition: bright galaxy
pref label: bright galaxy
related: LocalGroup
related: nearbyGalaxy

brightNebula
type: Concept
broader: nebula
definition: bright nebula
pref label: bright nebula

brightness
type: Concept
broader: opticalProperty
definition: brightness
narrower: surfaceBrightness
pref label: brightness
related: brightStar
related: illumination
related: integrationTime
related: intensity
related: luminosity
related: magnitude

brightnessDistribution
type: Concept
definition: brightness distribution
pref label: brightness distribution
scope note: see luminosity distribution

brightnessTemperature
type: Concept
broader: temperature
definition: brightness temperature
pref label: brightness temperature
related: blackBodyRadiation
related: luminosityDistribution
related: opticalProperty

brightPoint
type: Concept
definition: solar bright point
history note: FVH: new (2007-OCT-29)
pref label: bright point
related: Sun

brightStar
type: Concept
broader: highLuminosityStar
broader: star
change note: FVH: correction from original IAU to reflect flux, not necessarily luminosity (2007-OCT-1)
definition: bright star
pref label: bright star
related: brightness

brillouinScattering
type: Concept
definition: Brillouin scattering
pref label: brillouin scattering
related: MieScattering
related: brillouinSpectrum

brillouinSpectrum
type: Concept
broader: spectrum
definition: Brillouin spectrum
pref label: brillouin spectrum
related: brillouinScattering
related: lightScattering

broadBandPhotometry
type: Concept
alt label: wide-band photometry
broader: CcdPhotometry
broader: photoelectricPhotometry
broader: photographicPhotometry
change note: FVH: added BESSEL_PHOTOMETRY, GUNN_PHOTOMETRY, HST_PHOTOMETRY, KRON_COUSINS_PHOTOMETRY, SLOAN_PHOTOMETRY (2007-SEP-21)
definition: broad-band photometry
narrower: BesselPhotometry
narrower: BvPhotometry
narrower: CapePhotometry
narrower: CapeRiPhotometry
narrower: GunnPhotometry
narrower: HstPhotometry
narrower: JohnsonPhotometry
narrower: KronCousinsPhotometry
narrower: SloanPhotometry
narrower: infraredPhotometry
narrower: rgbPhotometry
narrower: rguPhotometry
narrower: twoColorPhotometry
narrower: ultravioletPhotometry
pref label: broad band photometry
related: mediumBandPhotometry
related: narrowBandPhotometry

bromine
type: Concept
alt label: Br
broader: fundamentalChemicalElement
definition: bromine (atomic number 35)
history note: FVH: new (2007-OCT-25)
pref label: bromine

brownDwarf
type: Concept
broader: lateTypeDwarf
broader: lateTypeSubdwarf
broader: stellarObject
definition: brown dwarf
narrower: LDwarf
narrower: LSubdwarf
narrower: TDwarf
narrower: TSubdwarf
pref label: brown dwarf
related: dwarf
related: lowMassStar
related: planetar

BStar
type: Concept
broader: ObStar
broader: earlyTypeStar
broader: youngStar
definition: B star
narrower: 53PerseiStar
narrower: BDwarf
narrower: BGiant
narrower: BSubdwarf
narrower: BSupergiant
narrower: BeStar
narrower: BpStar
narrower: BwStar
narrower: mercuryManganeseStar
pref label: B star
related: OCluster
related: earlyTypeVariableStar
related: spectralType

BSubdwarf
type: Concept
broader: BStar
broader: subdwarf
definition: B subdwarf star
pref label: B subdwarf

BSupergiant
type: Concept
broader: BStar
broader: ObSupergiant
broader: earlyTypeSupergiant
broader: supergiant
definition: B supergiant star
pref label: B supergiant

bubble
type: Concept
definition: bubble
narrower: interstellarBubble
pref label: bubble

bulge
type: Concept
definition: bulge
narrower: GalacticBulge
pref label: bulge
related: galaxyStructure
scope note: combine with other terms

BurkertProfile
type: Concept
broader: massDistribution
definition: Burkert mass-profile
history note: FVH: new (2007-OCT-5)
pref label: Burkert profile
related: NavarroFrenkWhiteProfile
related: exponentialProfile
related: isothermalSphere

burst
type: Concept
definition: burst
narrower: XRayBurst
narrower: gammaRayBurst
narrower: opticalBurst
narrower: outburst
narrower: radioBurst
narrower: rapidBurst
pref label: burst
related: burster
related: flare

burster
type: Concept
definition: burster
pref label: burster
related: XRayBurst
related: burst
related: gammaRayBurst
related: opticalBurst
related: radioBurst

butterflyDiagram
type: Concept
definition: butterfly diagram
pref label: butterfly diagram
related: solarActivity
related: solarCycle
related: sunspot
related: sunspotCycle
related: sunspotNumber

BvPhotometry
type: Concept
broader: broadBandPhotometry
broader: twoColorPhotometry
change note: FVH: added NT BESSEL_PHOTOMETRY, moved TWO-COLOR to BT and JOHNSON to NT (2007-SEP-21)
definition: BV photometry
pref label: BV photometry
related: BesselPhotometry
related: JohnsonPhotometry

BwStar
type: Concept
broader: BStar
broader: heliumPoorStar
definition: Bw star
pref label: Bw star

ByDraconisStar
type: Concept
broader: flareStar
definition: BY Draconis star
pref label: BY Draconis star
related: starspot

cadmium
type: Concept
alt label: Cd
broader: fundamentalChemicalElement
definition: cadmium (atomic number 48)
history note: FVH: new (2007-OCT-25)
pref label: cadmium

caesium
type: Concept
alt label: Cs
alt label: cesium
broader: fundamentalChemicalElement
definition: caesium (atomic number 55)
history note: FVH: new (2007-OCT-25)
pref label: caesium

CaIiEmissionLine
type: Concept
broader: calciumLine
broader: emissionLine
broader: metalLine
definition: Ca II emission line
pref label: Ca II emission line
related: WilsonBappuEffect

calcium
type: Concept
alt label: Ca
broader: fundamentalChemicalElement
definition: calcium (atomic number 20)
history note: FVH: new (2007-OCT-25)
pref label: calcium
related: calciumLine

calciumLine
type: Concept
broader: metalLine
broader: spectralLine
definition: calcium line
narrower: CaIiEmissionLine
narrower: HAndKLine
narrower: KLine
pref label: calcium line
related: absorptionLine
related: calcium

calendar
type: Concept
definition: calendar
narrower: GregorianCalendar
narrower: JulianCalendar
pref label: calendar
related: ephemeris
related: time

calibration
type: Concept
definition: calibration
narrower: biasCalibration
narrower: darkCurrentCalibration
narrower: deadTimeCalibration
narrower: linearityCalibration
narrower: selfCalibrationMethod
pref label: calibration
related: comparisonLamp
related: flatFieldLamp
related: instrument
related: lamp
related: measuringInstrument
related: reseaux
scope note: combine with other terms

californium
type: Concept
alt label: Cf
broader: fundamentalChemicalElement
definition: californium (atomic number 98)
history note: FVH: new (2007-OCT-25)
pref label: californium

camera
type: Concept
broader: opticalInstrument
broader: photographicInstrument
definition: camera
narrower: SchmidtCamera
narrower: allSkyCamera
narrower: astrographicCamera
narrower: ultravioletCamera
narrower: webcam
pref label: camera
related: allSkyPhotography
related: cameraLens
related: coronagraph
related: filterWheel
related: flatFieldLamp
related: photograph
related: photography
related: shutter
related: ultravioletPhotography
related: wideAngleLens
scope note: photographic type only here

cameraLens
type: Concept
broader: lens
definition: camera lens
pref label: camera lens
related: camera

canyon
type: Concept
broader: surfaceOfCelestialBody
definition: canyon
history note: FVH: new (2007-OCT-3)
pref label: canyon

CapePhotometry
type: Concept
alt label: UCBV photometry
broader: broadBandPhotometry
broader: photometricSystem
definition: Cape photometry
pref label: Cape photometry
related: CapeRiPhotometry
related: JohnsonPhotometry
related: KapteynSelectedArea

CapeRiPhotometry
type: Concept
broader: broadBandPhotometry
definition: Cape RI photometry
pref label: Cape RI photometry
related: CapePhotometry
related: JohnsonPhotometry

capture
type: Concept
definition: capture
pref label: capture
related: absorption
scope note: combine with other terms

carbonaceousChondrite
type: Concept
broader: chondrite
definition: carbonaceous chondrite
pref label: carbonaceous chondrite

carbonBurning
type: Concept
broader: nuclearFusion
broader: nucleosynthesis
definition: carbon burning
pref label: carbon burning
related: carbon
related: carbonFlash
related: giant
related: heliumBurning
related: hydrogenBurning
related: nuclearReaction
related: oxygenBurning
related: shellBurning
related: siliconBurning
related: stellarEvolution
related: stellarInterior

carbon
type: Concept
alt label: C
broader: fundamentalChemicalElement
definition: carbon (atomic number 6)
history note: FVH: new (2007-OCT-25)
pref label: carbon
related: carbonBurning
related: carbonCompound
related: carbonNitrogenCycle

carbonCompound
type: Concept
broader: interstellarMolecule
definition: carbon compound
narrower: Cs
narrower: carbonDioxide
narrower: carbonDisulfide
narrower: carbonMonosulfide
narrower: carbonMonoxide
narrower: cyanoacetylene
narrower: cyanodiacetylene
narrower: cyanogen
narrower: cyanopolyene
narrower: hydratedCarbon
pref label: carbon compound
related: carbon

carbonDioxide
type: Concept
alt label: CO2
alt label: CO_2
broader: carbonCompound
broader: gas
definition: carbon dioxide
pref label: carbon dioxide

carbonDisulfide
type: Concept
broader: carbonCompound
definition: carbon disulfide
pref label: carbon disulfide

carbonFlash
type: Concept
alt label: carbon detonation
definition: carbon flash
pref label: carbon flash
related: carbonBurning
related: heliumFlash
related: nuclearFusion
related: redGiantTip

carbonLine
type: Concept
broader: metalLine
broader: spectralLine
definition: carbon line
narrower: CIEmission
pref label: carbon line

carbonMonosulfide
type: Concept
alt label: CS
broader: carbonCompound
definition: carbon monosulfide
pref label: carbon monosulfide

carbonMonoxide
type: Concept
alt label: CO
broader: carbonCompound
broader: gas
definition: carbon monoxide
pref label: carbon monoxide
related: SwanBand

carbonNitrogenCycle
type: Concept
alt label: CNO cycle
alt label: carbon cycle
broader: hydrogenBurning
definition: carbon nitrogen cycle
pref label: carbon nitrogen cycle
related: CnoAnomaly
related: carbon
related: nitrogen
related: nuclearFusion
related: protonProtonReaction
related: stellarInterior

carbonStar
type: Concept
alt label: C star
broader: lateTypeGiant
definition: carbon star
pref label: carbon star
related: ChStar
related: CnStar
related: RStar
related: SStar
related: WolfRayetStar

CassegrainAntenna
type: Concept
alt label: Cassegrain antennas
alt label: two reflector antennas
alt label: two-reflector antennas
broader: antenna
broader: radioTelescope
definition: Cassegrain antenna
pref label: Cassegrain antenna
related: secondaryMirror
related: subreflector

CassegrainFocus
type: Concept
broader: CassegrainTelescope
broader: focus
definition: Cassegrain focus
pref label: Cassegrain focus
related: CoudeFocus
related: NasmythFocus
related: NewtonianFocus
related: parabolicAntenna
related: primeFocus
related: secondaryMirror
related: subreflector

CassegrainTelescope
type: Concept
broader: telescope
definition: Cassegrain telescope
narrower: CassegrainFocus
pref label: Cassegrain telescope

cataclysmicVariableStar
type: Concept
alt label: CV
alt label: cataclysmic binary star
alt label: eruptive variable star
broader: XRayBinaryStar
broader: closeBinaryStar
broader: eruptiveBinaryStar
broader: interactingBinaryStar
broader: variableStar
definition: cataclysmic variable star
narrower: AmHerculisStar
narrower: SxArietisStar
narrower: UvPerseiStar
narrower: classicalNova
narrower: dwarfNova
narrower: novaLikeVariable
pref label: cataclysmic variable star
related: eruption
related: lowMassXRayBinaryStar
related: massExchange
related: massLoss
related: opticalOutburst
related: supernova
related: symbioticStar
related: whiteDwarf

catadioptricSystem
type: Concept
broader: opticalSystem
definition: catadioptric system
narrower: BakerNunnCamera
narrower: BouwersTelescope
narrower: MaksutovTelescope
narrower: SchmidtTelescope
pref label: catadioptric system
related: correctorPlate
related: fieldCorrector
related: lens
related: mirror
related: opticalTelescope

catalog
type: Concept
alt label: catalogues UK
definition: catalog
narrower: HenryDraperCatalog
narrower: astrographicCatalog
narrower: radioSourceCatalog
pref label: catalog
related: FkCatalogSystem
related: atlas
related: ephemeris
related: findingList
related: fundamentalStar
related: map
related: nomenclature
related: skySurvey
related: survey
related: ultravioletSurvey
scope note: e.g. radio, star, x ray, etc.; combine with other terms

catastropheTheory
type: Concept
definition: catastrophe theory
pref label: catastrophe theory
related: mathematicalAnalysis

cathode
type: Concept
broader: electrode
definition: cathode
narrower: photocathode
pref label: cathode
related: photomultiplierTube
related: quantumEfficiency
related: thermionicEmission

catoptricSystem
type: Concept
broader: opticalSystem
definition: catoptric system
pref label: catoptric system
related: mirror
related: opticalTelescope

caustic
type: Concept
definition: caustic
history note: FVH: new (2007-OCT-8)
pref label: caustic
related: causticCrossing
related: cuspCrossing
related: gravitationalLensing

causticCrossing
type: Concept
definition: caustic crossing
history note: FVH: new (2007-OCT-8)
pref label: caustic crossing
related: caustic
related: cusp
related: cuspCrossing
related: gravitationalLensing

CcdDetector
type: Concept
alt label: CCD camera
broader: multiChannelDetector
broader: twoDimensionalDetector
definition: CCD detector
pref label: CCD detector
related: CcdObservation
related: CcdPhotometry
related: biasCalibration
related: chargeCoupledDevice
related: darkCurrentCalibration
related: photometer
related: televisionDetector

CcdObservation
type: Concept
broader: observation
definition: CCD observation
pref label: CCD observation
related: CcdDetector
related: CcdPhotometry
related: chargeCoupledDevice

CcdPhotometry
type: Concept
broader: photometry
definition: CCD photometry
narrower: broadBandPhotometry
narrower: mediumBandPhotometry
narrower: narrowBandPhotometry
pref label: CCD photometry
related: CcdDetector
related: CcdObservation
related: chargeCoupledDevice
related: photoelectricPhotometry
related: photographicPhotometry

cDGalaxy
type: Concept
broader: DGalaxy
broader: ellipticalGalaxy
broader: giantGalaxy
broader: massiveGalaxy
definition: cD galaxy (compact D galaxy in the Yerkes classification scheme)
pref label: cD galaxy
related: YerkesClassification
related: galaxyCluster
related: giantRadioGalaxy
related: nucleusCelestialObject

celestialCoordinateSystem
type: Concept
broader: coordinateSystem
definition: celestial coordinate system
history note: FVH: new (2007-NOV-2)
narrower: GalacticCoordinateSystem
narrower: eclipticCoordinateSystem
narrower: equatorialCoordinateSystem
narrower: supergalacticCoordinateSystem
pref label: celestial coordinate system

celestialEquator
type: Concept
broader: equatorialCoordinateSystem
definition: celestial equator
pref label: celestial equator
related: Declination
related: RightAscension
related: celestialPole
related: celestialSphere
related: equatorCorrection
related: equatorDetermination
related: equatorPosition
related: equinox
related: obliquityOfEcliptic

celestialMechanics
type: Concept
broader: scientificField
definition: celestial mechanics
pref label: celestial mechanics
related: KeplerianOrbit
related: LagrangianPoint
related: NBodyProblem
related: angularVelocity
related: astrodynamics
related: astrometry
related: astronomicalConstant
related: gravitation
related: gravitationalWave
related: lunarTheory
related: orbit
related: orbitalElement
related: orbitalEvolution
related: orbitalMotion
related: orbitalTheory
related: osculatoryElement
related: perturbation
related: perturbationTheory
related: planetaryAlignment
related: planetaryTheory
related: precession
related: threeBodyProblem
related: twoBodyProblem

celestialPole
type: Concept
broader: equatorialCoordinateSystem
broader: pole
definition: celestial pole
narrower: NorthCelestialPole
narrower: SouthCelestialPole
pref label: celestial pole
related: celestialEquator
related: celestialSphere
related: equator
related: polarAxis

celestialSphere
type: Concept
definition: celestial sphere
pref label: celestial sphere
related: celestialEquator
related: celestialPole
related: horizon
related: meridian
related: zenith

celsiusTemperatureScale
type: Concept
broader: temperatureScale
definition: Celsius temperature scale
pref label: celsius temperature scale
related: Kelvin
related: absoluteTemperatureScale
related: temperature

center
type: Concept
definition: center
pref label: center
scope note: combine with other terms

centerOfMass
type: Concept
broader: orbitalElement
definition: center of mass
pref label: center of mass
related: binaryStar
related: pericenter
related: planet

centralStar
type: Concept
broader: star
definition: central star
pref label: central star
related: planetaryNebula

centrifugalForce
type: Concept
broader: force
definition: centrifugal force
pref label: centrifugal force
related: centripetalForce

centripetalForce
type: Concept
broader: force
definition: centripetal force
pref label: centripetal force
related: centrifugalForce

Cepheid
type: Concept
alt label: Cepheid variable star
alt label: bump Cepheid
alt label: classical Cepheid
alt label: delta Cephei star
broader: pulsatingVariableStar
definition: Cepheid
narrower: doubleModeCepheid
narrower: youngDiskCepheid
pref label: Cepheid
related: BaadeWesselinkMethod
related: BlHerculisStar
related: CepheidDistance
related: HeIiIonizationZone
related: RrLyraeStar
related: WVirginisStar
related: dwarfCepheid
related: instabilityStrip
related: kappaMechanism
related: periodAgeRelation
related: periodColorRelation
related: periodLuminosityColorRelation
related: periodLuminosityRelation
related: periodRadiusRelation
related: periodSpectrumRelation
related: radialPulsation
related: radiusLuminosityRelation
scope note: most commonly used term

CepheidDistance
type: Concept
broader: distanceMeasurement
definition: Cepheid distance
history note: ES: new (2007-OCT-8)
pref label: Cepheid distance
related: Cepheid

CerenkovCounter
type: Concept
alt label: Cherenkov counter
broader: scintillationCounter
definition: Cerenkov counter
pref label: Cerenkov counter
related: CerenkovRadiation
related: cosmicRay
scope note: American spelling

CerenkovRadiation
type: Concept
alt label: Cerenkov effect
broader: electromagneticRadiation
broader: radiation
definition: Cerenkov radiation
pref label: Cerenkov radiation
related: CerenkovCounter
related: cosmicRay
related: gammaRayRadiation
related: nuclearRadiation
related: radiationMechanism
related: ultravioletRadiation
scope note: American spelling

Ceres
type: Concept
broader: dwarfPlanet
definition: Ceres
history note: FVH: new (2007-OCT-2)
pref label: Ceres
related: SolarSystem

cerium
type: Concept
alt label: Ce
broader: fundamentalChemicalElement
broader: rareEarth
definition: cerium (atomic number 58)
history note: FVH: new (2007-OCT-25)
pref label: cerium

ChandlerWobble
type: Concept
alt label: polar wandering
definition: Chandler wobble
pref label: Chandler wobble
related: EarthRotation
related: latitudeDetermination
related: latitudeVariation
related: polarMotion

ChandrasekharMass
type: Concept
broader: mass
definition: Chandrasekhar limit
definition: Chandrasekhar limit; the mass-limit for a degenerate stellar object
pref label: Chandrasekhar mass
related: gravitationalCollapse
related: hydrogenBurning
related: massRadiusRelation
related: stellarInterior
related: whiteDwarf

ChandrasekharSchoenbergLimit
type: Concept
alt label: Chandrasekhar-Schonberg limit
alt label: Schoenberg-Chandrasekhar limit
alt label: Schonberg-Chandrasekhar limit
broader: mass
definition: Chandrasekhar-Schoenberg limit; the mass-limit for an isothermal stellar core
pref label: Chandrasekhar-Schoenberg limit
related: gravitationalCollapse
related: hydrogenBurning
related: massRadiusRelation
related: stellarInterior

chargeCoupledDevice
type: Concept
alt label: CCD
alt label: charge coupled device
broader: photoelectronicDevice
broader: semiconductorDevice
change note: FVH: added RT READ_OUT_NOISE (2007-SEP-21)
definition: charge-coupled device
pref label: charge-coupled device
related: CcdDetector
related: CcdObservation
related: CcdPhotometry
related: detector
related: multiChannelDetector
related: quantumEfficiency
related: readOutNoise
related: twoDimensionalDetector
scope note: use abbreviated form (CCD) when combined with other terms

chargeInjectionDevice
type: Concept
alt label: CID
alt label: charge injection device
broader: photoelectronicDevice
broader: semiconductorDevice
definition: charge-injection device
pref label: charge-injection device
related: detector
related: twoDimensionalDetector

chargeTransferDevice
type: Concept
alt label: CCD
alt label: charge transfer device
broader: photoelectronicDevice
broader: semiconductorDevice
definition: charge-transfer device
pref label: charge-transfer device
related: detector
related: twoDimensionalDetector

chemicalComposition
type: Concept
definition: chemical composition
pref label: chemical composition
related: abundance
related: peculiarStar

chemicalElement
type: Concept
definition: chemical element
narrower: fundamentalChemicalElement
narrower: heavyElement
narrower: isotope
narrower: traceElement
pref label: chemical element
related: abundance
related: atom
related: curveOfGrowth
related: elementFormation
related: metalAbundance
related: origin
scope note: see appendix

chemicalEvolution
type: Concept
definition: chemical evolution
narrower: enrichment
pref label: chemical evolution
related: abundance
related: stellarEvolution

chemiluminescence
type: Concept
broader: luminescence
definition: chemiluminescence
pref label: chemiluminescence
related: lightEmission

chemistry
type: Concept
broader: scientificField
definition: chemistry
narrower: cosmochemistry
pref label: chemistry

chlorine
type: Concept
alt label: Cl
broader: fundamentalChemicalElement
definition: chlorine (atomic number 17)
history note: FVH: new (2007-OCT-25)
pref label: chlorine

chondrite
type: Concept
broader: meteorite
definition: chondrite
narrower: achondrite
narrower: carbonaceousChondrite
narrower: chondrules
pref label: chondrite
related: australite
related: bediasite
related: moldavite

chondrules
type: Concept
broader: chondrite
definition: chondrules
pref label: chondrules

chromaticAberration
type: Concept
broader: opticalAberration
definition: chromatic aberration
pref label: chromatic aberration
related: astigmatism
related: comaticAberration
related: distortion
related: fieldCurvature
related: opticalSystem
related: sphericalAberration

chromium
type: Concept
alt label: Cr
broader: fundamentalChemicalElement
definition: chromium (atomic number 24)
history note: FVH: new (2007-OCT-25)
pref label: chromium

chromosphere
type: Concept
definition: chromosphere
pref label: chromosphere
related: Sun
related: coronalLoop
related: facula
related: fibrill
related: flashSpectrum
related: macroSpicule
related: mottle
related: photosphere
related: plage
related: prominence
related: quiescentProminence
related: solarAtmosphere
related: solarFilament
related: spicule
related: stellarAtmosphere
related: stellarWind
related: transitionRegion

chronometer
type: Concept
alt label: chronograph
broader: clock
broader: measuringInstrument
definition: chronometer
pref label: chronometer
related: time

ChStar
type: Concept
broader: giant
definition: CH star
pref label: CH star
related: carbonStar

CIEmission
type: Concept
broader: carbonLine
broader: emissionSpectrum
definition: C I emission
pref label: C I emission

CIiRegion
type: Concept
broader: interstellarMatter
definition: C II region
pref label: C II region
related: darkCloud

circularOrbit
type: Concept
broader: ellipticalOrbit
definition: circular orbit
pref label: circular orbit
related: hyperbolicOrbit
related: orbitalMotion
related: parabolicOrbit

circularPolarization
type: Concept
alt label: circular polarisation UK
broader: lightPolarization
change note: FVH: added RT QUARTER_WAVE_PLATES (2007-SEP-21)
definition: circular polarization
pref label: circular polarization
related: planePolarization
related: quarterWavePlate

circumplanetaryMatter
type: Concept
broader: matter
definition: circumplanetary matter
pref label: circumplanetary matter
related: circumstellarMatter

circumstellarDisk
type: Concept
broader: disk
broader: rotatingBody
definition: circumstellar discs UK
definition: circumstellar disk
pref label: circumstellar disk
related: accretionDisk
related: circumstellarGas
related: circumstellarMatter
related: massLoss
related: torus

circumstellarDust
type: Concept
broader: circumstellarGrain
broader: circumstellarMatter
definition: circumstellar dust
pref label: circumstellar dust
related: RCoronaeBorealisStar
related: circumstellarGas
related: cocoonStar
related: dustShell

circumstellarEnvelope
type: Concept
alt label: stellar envelope
broader: circumstellarMatter
definition: circumstellar envelope
narrower: expandingEnvelope
pref label: circumstellar envelope
related: WolfRayetStar
related: circumstellarGas
related: circumstellarShell
related: massLoss

circumstellarGas
type: Concept
broader: circumstellarMatter
definition: circumstellar gas
pref label: circumstellar gas
related: circumstellarDisk
related: circumstellarDust
related: circumstellarEnvelope
related: circumstellarGrain
related: circumstellarShell

circumstellarGrain
type: Concept
broader: circumstellarMatter
definition: circumstellar grain
narrower: circumstellarDust
pref label: circumstellar grain
related: RCoronaeBorealisStar
related: circumstellarGas

circumstellarMatter
type: Concept
alt label: circumstellar cloud
alt label: stellar envelope
broader: matter
definition: circumstellar matter
narrower: circumstellarDust
narrower: circumstellarEnvelope
narrower: circumstellarGas
narrower: circumstellarGrain
pref label: circumstellar matter
related: bipolarOutflow
related: circumplanetaryMatter
related: circumstellarDisk
related: circumstellarShell
related: corona
related: expandingEnvelope
related: gravitatingDisk
related: interplanetaryMatter
related: interstellarMatter
related: massLoss

circumstellarShell
type: Concept
alt label: stellar envelope
broader: shell
definition: circumstellar shell
narrower: dustShell
narrower: rotatingShell
pref label: circumstellar shell
related: BeStar
related: circumstellarEnvelope
related: circumstellarGas
related: circumstellarMatter
related: extremeCarbonStar
related: massLoss
related: shellStar
related: stellarWind

civilTime
type: Concept
broader: time
definition: civil time
pref label: civil time
related: UniversalTime
related: ephemerisTime
related: meanSolarTime
related: siderealTime

classicalNova
type: Concept
alt label: nova
broader: cataclysmicVariableStar
broader: nova
definition: classical nova
history note: FVH: new (2007-NOV-15)
pref label: classical nova

classicalTTauriStar
type: Concept
alt label: CTTS
broader: TTauriStar
definition: classical T Tauri star
history note: FVH: new (2007-SEP-24)
pref label: classical T Tauri star

classification
type: Concept
definition: classification
narrower: luminosityClassification
narrower: spectralClassification
pref label: classification
related: morphology
related: nomenclature
related: taxonomy
scope note: combine with other terms

cleanMethod
type: Concept
definition: clean method
pref label: clean method
related: dataProcessing
related: imageProcessing
related: imageReconstruction
related: radioAstronomy

clock
type: Concept
broader: measuringInstrument
broader: timingEquipment
definition: clock
narrower: atomicClock
narrower: chronometer
pref label: clock
related: time
related: timeStandard

closeBinaryStar
type: Concept
broader: binaryStar
definition: close binary star
narrower: ZAndromedaeStar
narrower: betaLyraeStar
narrower: cataclysmicVariableStar
narrower: ellipsoidalVariableStar
narrower: semiDetachedBinaryStar
pref label: close binary star
related: RocheLimit
related: RocheLobe
related: XRayBrightPoint
related: accretionDisk
related: contactBinaryStar
related: synchronousRotation
related: tidalFriction

closedUniverse
type: Concept
broader: cosmology
definition: closed universe
pref label: closed universe
related: BigBangTheory
related: openUniverse
related: steadyStateTheory

closeEncounter
type: Concept
definition: close encounter
pref label: close encounter
related: stellarDynamics

cloud
type: Concept
definition: cloud
narrower: collapsingCloud
narrower: dustCloud
narrower: gasCloud
narrower: highVelocityCloud
narrower: noctilucentCloud
narrower: plasmaCloud
pref label: cloud
related: EarthAtmosphere
related: cloudMonitor
scope note: combine with other terms

cloudMonitor
type: Concept
broader: allSkyCamera
definition: cloud monitor
history note: FVH: new (2007-SEP-21)
pref label: cloud monitor
related: EarthAtmosphere
related: cloud

clumping
type: Concept
definition: clumping
pref label: clumping
scope note: combine with other terms

cluster
type: Concept
definition: cluster
narrower: galaxyCluster
narrower: protocluster
narrower: starCluster
pref label: cluster

clustering
type: Concept
definition: clustering
pref label: clustering
related: galaxyCluster
related: starCluster
scope note: combine with other terms

CnoAnomaly
type: Concept
broader: anomaly
definition: CNO anomaly
pref label: CNO anomaly
related: abundance
related: abundanceRatio
related: carbonNitrogenCycle
related: metalAbundance

CnStar
type: Concept
broader: giant
definition: cn star
pref label: CN star
related: carbonStar
scope note: carbon-nitrogen star

coating
type: Concept
definition: coating
narrower: aluminumCoating
narrower: antireflectionCoating
narrower: silverCoating
pref label: coating
related: lens
related: mirror
related: thinFilm
related: vaporDeposition
scope note: combine with other terms

cobalt
type: Concept
alt label: Co
broader: fundamentalChemicalElement
definition: cobalt (atomic number 27)
history note: FVH: new (2007-OCT-25)
pref label: cobalt
related: magneticStar

cocoonStar
type: Concept
broader: infraredSource
definition: cocoon star
pref label: cocoon star
related: circumstellarDust

coelostat
type: Concept
broader: reflectingTelescope
definition: coelostat
narrower: heliostat
pref label: coelostat
related: drive
related: siderostat
related: telescopeMounting

coherence
type: Concept
definition: coherence
narrower: lightCoherence
pref label: coherence
related: laser
related: maser
scope note: combine with other terms

coldDarkMatter
type: Concept
broader: DarkMatter
change note: FVH: added RT DARK_ENERGY (2007-SEP-21)
definition: cold Dark Matter
pref label: cold Dark Matter
related: DarkEnergy
related: baryonicDarkMatter
related: cosmology

collapse
type: Concept
definition: collapse
narrower: gravitationalCollapse
pref label: collapse
scope note: combine with other terms

collapsedStar
type: Concept
alt label: collapsed object
alt label: collapsing star
broader: star
definition: collapsed star
narrower: blackHole
narrower: neutronStar
narrower: pulsar
narrower: stellarBlackHole
pref label: collapsed star
related: degenerateStar
related: stellarEvolution
related: whiteDwarf

collapsingCloud
type: Concept
broader: cloud
definition: collapsing cloud
narrower: protoplanetaryNebula
pref label: collapsing cloud
related: protocluster
related: protogalaxy
related: protostar

collimation
type: Concept
definition: collimation
pref label: collimation
related: adjustment
related: alignmentOptics
related: correction
related: optics
related: orientation

collimator
type: Concept
definition: collimator
pref label: collimator
related: beamWaveguide
related: lens
related: mirror
related: opticalInstrument

collisionalExcitation
type: Concept
broader: collisionProcess
definition: collisional excitation
pref label: collisional excitation
related: collisionBroadening
related: collisionSpectroscopy
related: collisionStrength
related: ion
related: ionizedGas
related: spectroscopy

collisionalPlasma
type: Concept
broader: plasma
definition: collisional plasma
pref label: collisional plasma
related: collisionProcess
related: ion
related: shock

collisionBroadening
type: Concept
broader: collisionProcess
broader: lineBroadening
definition: collision broadening
pref label: collision broadening
related: collisionSpectroscopy
related: collisionStrength
related: collisionalExcitation
related: spectroscopicAnalysis

collision
type: Concept
definition: collision
pref label: collision
related: galaxy
related: meteorite
related: planet
scope note: combine with other terms

collisionProcess
type: Concept
definition: collision process
narrower: collisionBroadening
narrower: collisionalExcitation
pref label: collision process
related: collisionStrength
related: collisionalPlasma

collisionSpectroscopy
type: Concept
broader: spectroscopy
definition: collision spectroscopy
pref label: collision spectroscopy
related: collisionBroadening
related: collisionStrength
related: collisionalExcitation

collisionStrength
type: Concept
definition: collision strength
pref label: collision strength
related: collisionBroadening
related: collisionProcess
related: collisionSpectroscopy
related: collisionalExcitation

color
type: Concept
broader: opticalProperty
definition: color
pref label: color
related: colorEquation
related: colorExcess
related: colorLuminosityRelation
related: colorMagnitudeRelation
related: colorPhotography
related: colorRedshiftRelation
related: colorimetry
related: electromagneticRadiation
related: photometry
related: spectrophotometry
related: temperature
related: visibleRadiation

colorEquation
type: Concept
definition: color equation
pref label: color equation
related: color
related: photometry

colorExcess
type: Concept
definition: color excess
pref label: color excess
related: color
related: interstellarReddening
related: photometry

colorimetry
type: Concept
definition: colorimetry
pref label: colorimetry
related: color

colorIndex
type: Concept
definition: color index
pref label: color index
related: intrinsicColor
related: photometry
related: twoColorDiagram

colorLuminosityRelation
type: Concept
alt label: color luminosity relation
definition: color-luminosity relation
pref label: color-luminosity relation
related: HertzsprungRussellDiagram
related: color
related: photometry

colorMagnitudeRelation
type: Concept
alt label: c m diagram
alt label: c m relation
alt label: c-m diagram
alt label: c-m relation
alt label: color magnitude relation
alt label: color-magnitude diagram
definition: color-magnitude relation
pref label: color-magnitude relation
related: HertzsprungRussellDiagram
related: color
related: photometry

colorPhotography
type: Concept
broader: photography
definition: color photography
pref label: color photography
related: color

colorRedshiftRelation
type: Concept
alt label: color redshift relation
definition: color-redshift relation
pref label: color-redshift relation
related: color
related: cosmology
related: observationalCosmology

colorVision
type: Concept
broader: vision
definition: color vision
pref label: color vision
related: darkAdaption

coma
type: Concept
definition: coma
pref label: coma
related: comet
related: galaxy

comaticAberration
type: Concept
alt label: coma
broader: opticalAberration
change note: FVH: renamed after general conversion to singular (2007-11-27)
definition: comatic aberration (coma)
pref label: comatic aberration
related: astigmatism
related: chromaticAberration
related: distortion
related: fieldCurvature
related: opticalSystem
related: sphericalAberration

cometaryGlobule
type: Concept
broader: darkNebula
broader: globule
broader: interstellarMatter
definition: cometary globule
history note: FVH: new (2007-SEP-21)
pref label: cometary globule
related: BokGlobule
related: HIiRegion
related: protostar
related: starFormation

comet
type: Concept
broader: rotatingBody
definition: comet
narrower: KreutzSungrazer
narrower: aperiodicComet
narrower: longPeriodComet
narrower: periodicComet
pref label: comet
related: OortCloud
related: SolarSystem
related: coma
related: dirtySnowballTheory
related: dust
related: envelope
related: halo
related: interplanetaryMatter
related: jet
related: meteorStream
related: meteorite
related: meteoroid
related: meteoroidDustCloud
related: nucleusCelestialObject
related: parabolicOrbit
related: streamer
related: tail
scope note: named comet not included

compactGalaxy
type: Concept
broader: peculiarGalaxy
definition: compact galaxy
narrower: NGalaxy
pref label: compact galaxy
related: BlLacertaeObject
related: activeGalaxy
related: quasar

compactHIiRegion
type: Concept
broader: HIiRegion
definition: compact H II region
pref label: compact H II region

compactNebula
type: Concept
broader: nebula
definition: compact nebula
pref label: compact nebula

compactNucleus
type: Concept
broader: galacticNucleus
broader: nucleusCelestialObject
definition: compact nucleus
narrower: SeyfertNucleus
pref label: compact nucleus
related: SeyfertGalaxy
related: activeGalacticNucleus
related: compactSource

compactObject
type: Concept
definition: compact object
narrower: BlLacertaeObject
narrower: blackHole
narrower: compactSource
narrower: neutronStar
narrower: whiteDwarf
pref label: compact object

compactSource
type: Concept
broader: compactObject
broader: radioSource
broader: source
definition: compact source
pref label: compact source
related: compactNucleus
related: radioStructure

companionGalaxy
type: Concept
broader: galaxy
definition: companion galaxy
pref label: companion galaxy
related: doubleGalaxy
related: galaxyGroup

companionStar
type: Concept
broader: star
definition: companion star
narrower: primaryStar
narrower: secondaryStar
narrower: tertiaryStar
pref label: companion star
related: binaryStar
related: multipleStar

comparison
type: Concept
definition: comparison
pref label: comparison
scope note: combine with other terms

comparisonLamp
type: Concept
broader: lamp
definition: comparison lamp
history note: FVH: new (2007-SEP-21)
pref label: comparison lamp
related: calibration
related: spectrograph

comparisonStar
type: Concept
broader: standardStar
definition: comparison star
pref label: comparison star
related: variableStar

component
type: Concept
definition: component
pref label: component
scope note: combine with other terms

compositeParticle
type: Concept
broader: boson
definition: composite particle
narrower: alphaParticle
narrower: ion
narrower: radical
pref label: composite particle

composition
type: Concept
definition: composition
pref label: composition
related: planet
scope note: combine with other terms

ComptonEffect
type: Concept
definition: Compton effect
pref label: Compton effect
related: XRayScattering
related: electron
related: radiationScattering

ComptonScattering
type: Concept
broader: lightScattering
broader: radiationScattering
broader: scattering
definition: Compton scattering
narrower: ThomsonScattering
pref label: Compton scattering
related: RayleighScattering
related: electron
related: inverseComptonScattering

computerApplication
type: Concept
broader: computing
definition: computer application
narrower: computerSimulation
pref label: computer application

computer
type: Concept
definition: computer
narrower: arrayProcessor
narrower: microprocessor
narrower: parallelComputer
pref label: computer
related: computing
related: controlSystem
related: dataCenter
related: dataProcessing
related: dataReduction
related: dataStorage
related: peripheral

computerModel
type: Concept
broader: computing
broader: model
definition: computer model
pref label: computer model
related: computerProgram
related: computerSimulation
related: mathematicalModel
related: numericalSimulation

computerProgram
type: Concept
broader: computing
definition: computer program
pref label: computer program
related: computerModel
related: computerSimulation
related: dataProcessing

computerSimulation
type: Concept
broader: computerApplication
broader: simulation
definition: computer simulation
pref label: computer simulation
related: computerModel
related: computerProgram

computing
type: Concept
definition: computing
narrower: computerApplication
narrower: computerModel
narrower: computerProgram
narrower: dataProcessing
narrower: dataRetrieval
narrower: dataStorage
narrower: database
pref label: computing
related: computer

condensation
type: Concept
definition: condensation
pref label: condensation
scope note: combine with other terms

conduction
type: Concept
definition: conduction
pref label: conduction
related: energyTransfer
related: thermalConductivity
scope note: combine with other terms

conjunction
type: Concept
definition: conjunction
pref label: conjunction
related: opposition
related: quadrature
related: synodicPeriod
related: syzygy
scope note: refers to planet position

constant
type: Concept
change note: FVH: more physical hierarchy (2007-OCT-11)
definition: constant
narrower: astronomicalConstant
narrower: cosmologicalParameter
narrower: physicalConstant
pref label: constant

constellation
type: Concept
definition: constellation
pref label: constellation
related: astrology
related: zodiac
scope note: see appendix

contactBinaryStar
type: Concept
broader: binaryStar
definition: contact binary star
narrower: betaLyraeStar
narrower: ellipsoidalVariableStar
pref label: contact binary star
related: closeBinaryStar
related: eclipsingBinaryStar
related: equipotentialSurface
related: massExchange

continentalDrift
type: Concept
definition: continental drift
pref label: continental drift
related: continent
related: geomagnetism
related: geophysics
related: paleomagnetism

continent
type: Concept
definition: continent
pref label: continent
related: Earth
related: continentalDrift

continuousSpectrum
type: Concept
broader: spectrum
definition: continuous spectrum
pref label: continuous spectrum
related: lightEmission
related: spectroscopicAnalysis
related: spectroscopy
related: visibleSpectrum

continuumRadiation
type: Concept
broader: electromagneticRadiation
broader: radiation
definition: continuum radiation
narrower: XRayContinuum
narrower: ultravioletContinuum
pref label: continuum radiation
related: contiuum
related: photosphere

contiuum
type: Concept
definition: contiuum
pref label: contiuum
related: continuumRadiation
related: spectrum
scope note: combine with other terms

contourMap
type: Concept
broader: map
definition: contour map
pref label: contour map
related: isophot
related: radioStructure

contraction
type: Concept
definition: contraction
pref label: contraction
scope note: combine with other terms

contrast
type: Concept
definition: contrast
pref label: contrast
scope note: combine with other terms

controlSystem
type: Concept
definition: control system
narrower: autoguider
narrower: remoteControlSystem
pref label: control system
related: computer
related: drive
related: guideSystem
related: microprocessor
related: pointingAccuracy
related: pointingError
related: quadrantDetector
related: telescope
related: telescopeInstrument
related: tracking

convection
type: Concept
definition: convection
pref label: convection
related: HayashiTrack
related: RayleighNumber
related: convectiveEnvelope
related: convectiveShell
related: convectiveZone
related: dredgeUp
related: energyTransfer
related: envelope
related: granulation
related: lineBroadening
related: massTransfer
related: thermalInstability
related: thermalStructure
related: turbulenceEarthAtmosphere
related: turbulenceStarAtmosphere

convectiveEnvelope
type: Concept
definition: convective envelope
pref label: convective envelope
related: convection

convectiveShell
type: Concept
broader: shell
definition: convective shell
pref label: convective shell
related: convection

convectiveZone
type: Concept
definition: convective zone
pref label: convective zone
related: convection

cooling
type: Concept
definition: cooling
pref label: cooling
scope note: combine with other terms

coolingFlow
type: Concept
definition: cooling flow
pref label: cooling flow
related: accretionDisk
related: galaxy
related: starFormation

coordinatedUniversalTime
type: Concept
alt label: UTC
broader: UniversalTime
definition: coordinated Universal Time
history note: FVH: new (2007-OCT-3)
pref label: coordinated Universal Time
related: Ut1

coordinateSystem
type: Concept
definition: coordinate system
narrower: celestialCoordinateSystem
narrower: horizonCoordinateSystem
narrower: inertialCoordinateSystem
pref label: coordinate system
related: aberration
related: astrometry
related: heliocentricCorrection
related: position
related: referenceFrame
related: referenceSystem
related: sphericalCoordinate
related: truePosition
scope note: coordinate not included
scope note: planet and satellite surface

copper
type: Concept
alt label: Cu
broader: fundamentalChemicalElement
definition: copper (atomic number 29)
history note: FVH: new (2007-OCT-25)
pref label: copper

core
type: Concept
definition: core
pref label: core
related: Earth
related: planet
related: stellarInterior
scope note: combine with other terms

corona
type: Concept
alt label: coronas
definition: corona
narrower: ECorona
narrower: FCorona
narrower: KCorona
narrower: coronalHole
narrower: coronalLine
narrower: coronalLoop
narrower: coronalPlume
narrower: solarCorona
pref label: corona
related: circumstellarMatter
related: halo
related: ionization
related: massLoss
related: stellarAtmosphere

coronagraph
type: Concept
broader: instrument
broader: opticalInstrument
definition: coronagraph
pref label: coronagraph
related: camera
related: solarCorona
related: solarObservatory
related: spectroheliograph

coronalDimming
type: Concept
definition: solar coronal dimming
history note: FVH: new (2007-OCT-29)
pref label: coronal dimming
related: solarCorona

coronalHole
type: Concept
broader: corona
definition: coronal hole
pref label: coronal hole
related: solarCorona
related: solarWind

coronalLine
type: Concept
broader: corona
broader: emissionLine
definition: coronal line
pref label: coronal line
related: solarCorona

coronalLoop
type: Concept
broader: corona
definition: coronal loop
pref label: coronal loop
related: chromosphere
related: solarActivity
related: solarCorona

coronalMassEjection
type: Concept
alt label: CME
broader: massLoss
definition: coronal mass ejection
pref label: coronal mass ejection
related: corpuscularEmission
related: solarCorona

coronalPlume
type: Concept
broader: corona
definition: coronal plume
pref label: coronal plume
related: solarCorona

coronalTransient
type: Concept
definition: coronal transient
pref label: coronal transient
related: solarCorona

coronalWave
type: Concept
broader: AlfvenWave
definition: solar coronal wave
history note: FVH: new (2007-OCT-29)
pref label: coronal wave
related: solarCorona

corpuscularEmission
type: Concept
definition: corpuscular emission
pref label: corpuscular emission
related: coronalMassEjection

correction
type: Concept
definition: correction
pref label: correction
related: adjustment
related: alignmentOptics
related: collimation
related: error
related: selectionEffect
scope note: combine with other terms

correctorPlate
type: Concept
broader: lens
broader: opticalComponent
definition: corrector plate
pref label: corrector plate
related: SchmidtCamera
related: SchmidtTelescope
related: catadioptricSystem
related: fieldCorrector

correlation
type: Concept
definition: correlation
history note: FVH: new (2007-NOV-1)
narrower: autoCorrelation
narrower: crossCorrelation
narrower: interferometricCorrelation
narrower: luminosityDispersionRelation
pref label: correlation
related: interferometry
related: receiver

cosmicAbundance
type: Concept
broader: abundance
definition: cosmic abundance
pref label: cosmic abundance
related: cosmology

cosmicBackgroundRadiation
type: Concept
broader: backgroundRadiation
definition: cosmic background radiation
pref label: cosmic background radiation

cosmic
type: Concept
definition: cosmic
pref label: cosmic
scope note: combine with other terms

cosmicElectrodynamics
type: Concept
broader: electrodynamics
broader: electromagneticTheory
definition: cosmic electrodynamics
pref label: cosmic electrodynamics
related: magnetohydrodynamics

cosmicNoise
type: Concept
broader: noise
broader: radioInterference
definition: cosmic noise
narrower: microwaveBackground
pref label: cosmic noise
related: backgroundNoise
related: backgroundRadiation
related: microwaveEmission
related: radioBackground

cosmicRayAstronomy
type: Concept
broader: astronomy
definition: cosmic ray astronomy
pref label: cosmic ray astronomy
related: balloonBorneInstrument
related: highEnergyAstrophysics
related: rocketBorneInstrument
related: satelliteBorneInstrument

cosmicRay
type: Concept
alt label: cosmic radiation
alt label: primary cosmic ray
broader: backgroundRadiation
broader: highEnergyRadiation
broader: radiation
definition: cosmic ray
narrower: GalacticCosmicRay
pref label: cosmic ray
related: CerenkovCounter
related: CerenkovRadiation
related: cosmicRayShower
related: cosmicRaySource
related: forbushEffect
related: inverseComptonEffect
related: secondaryCosmicRay

cosmicRayShower
type: Concept
alt label: air shower
alt label: auger shower
definition: cosmic ray shower
pref label: cosmic ray shower
related: cosmicRay
related: phosphorescentScintillation
related: secondaryCosmicRay

cosmicRaySource
type: Concept
broader: source
definition: cosmic ray source
pref label: cosmic ray source
related: cosmicRay

cosmicString
type: Concept
alt label: string
definition: cosmic string
pref label: cosmic string
related: cosmology
related: intergalacticMatter
related: interstellarMatter
related: largeScaleStructure

cosmicYear
type: Concept
broader: year
definition: cosmic year
pref label: cosmic year
related: GalacticRotation

cosmochemistry
type: Concept
alt label: astrochemistry
alt label: cosmic chemistry
broader: chemistry
definition: cosmochemistry
pref label: cosmochemistry
related: astrobiology
related: cosmology
related: interstellarMolecule
related: molecularAstrophysics

cosmochronology
type: Concept
alt label: nucleocosmochronology
definition: cosmochronology
history note: ES: new (2007-OCT-8)
pref label: cosmochronology
related: age
related: cosmology
related: nuclearFission

cosmogony
type: Concept
broader: astronomy
definition: cosmogony
narrower: relativity
pref label: cosmogony
related: cosmology
related: protocluster
related: protogalaxy
related: protoplanetaryNebula
related: universe

cosmologicalConstant
type: Concept
alt label: Lambda
broader: cosmologicalParameter
change note: FVH: added ALT lambda (2007-SEP-21)
definition: cosmological constant
pref label: cosmological constant
related: DarkEnergy
related: OmegaLambda
related: cosmology

cosmologicalDistanceScale
type: Concept
broader: distanceScale
definition: cosmological distance scale
pref label: cosmological distance scale
related: HubbleConstant
related: cosmologicalParameter
related: decelerationParameter
related: observationalCosmology
related: redshift
related: redshiftDistanceRelation
related: redshiftMagnitudeRelation

cosmologicalModel
type: Concept
definition: cosmological model
pref label: cosmological model
scope note: see under cosmology

cosmologicalParameter
type: Concept
broader: constant
change note: FVH: renamed *_parameter, since some of them aren't necessarily constant (2007-OCT-26)
definition: cosmological parameter/constant
history note: FVH: new (2007-SEP-21)
narrower: HubbleConstant
narrower: OmegaParameter
narrower: cosmologicalConstant
narrower: decelerationParameter
narrower: sigma8
pref label: cosmological parameter
related: cosmologicalDistanceScale
related: cosmology

cosmology
type: Concept
broader: astronomy
change note: FVH: added RT DARK_ENERGY, RT LARGE_SCALE_STRUCTURE (2007-SEP-21)
definition: cosmology
narrower: BianchiCosmology
narrower: BigBangTheory
narrower: EinsteinUniverse
narrower: FriedmannUniverse
narrower: GoedelUniverse
narrower: LemaitreUniverse
narrower: closedUniverse
narrower: deSitterUniverse
narrower: diracCosmology
narrower: expandingUniverse
narrower: hierarchicalCosmology
narrower: inflationaryUniverse
narrower: openUniverse
narrower: oscillatingUniverse
narrower: primordialFireball
narrower: quantumCosmology
narrower: relativisticCosmology
narrower: steadyStateTheory
pref label: cosmology
related: DarkEnergy
related: DarkMatter
related: HubbleConstant
related: HubbleDiagram
related: HubbleLaw
related: HubbleRadius
related: HubbleTime
related: OmegaParameter
related: TullyFisherRelation
related: TypeIaSupernova
related: anthropicPrinciple
related: astrophysics
related: coldDarkMatter
related: colorRedshiftRelation
related: cosmicAbundance
related: cosmicString
related: cosmochemistry
related: cosmochronology
related: cosmogony
related: cosmologicalConstant
related: cosmologicalParameter
related: earlyUniverse
related: galaxyCount
related: galaxyDistribution
related: galaxyEvolution
related: generalTheoryOfRelativity
related: largeScaleStructure
related: microwaveBackground
related: missingMass
related: protocluster
related: protogalaxy
related: redshift
related: redshiftDistanceRelation
related: redshiftMagnitudeRelation
related: relativisticAstrophysics
related: relativisticVelocity
related: spaceTimeCurvature
related: stellarEvolution
related: universe
related: whiteHole

CoudeFocus
type: Concept
broader: focus
definition: Coude focus
pref label: Coude focus
related: CassegrainFocus
related: NasmythFocus
related: NewtonianFocus
related: primeFocus

CoudeSpectrograph
type: Concept
broader: spectrograph
definition: Coude spectrograph
pref label: Coude spectrograph
related: highResolutionSpectrosopy
related: highResolutionSpectrum

CoudeSpectrum
type: Concept
broader: highResolutionSpectrum
definition: Coude spectrum
pref label: Coude spectrum
related: echelleSpectrograph

counter
type: Concept
alt label: count
broader: measuringInstrument
definition: counter
narrower: scintillationCounter
pref label: counter
related: counting
related: dataAcquisition
related: photonCountingSystem

counting
type: Concept
alt label: count
definition: counting
pref label: counting
related: counter
related: dataAcquisition

coupling
type: Concept
definition: coupling
pref label: coupling
scope note: combine with other terms

crater
type: Concept
definition: crater
narrower: impactCrater
pref label: crater
related: Earth
related: Moon
related: basin
related: ejecta
related: meteor
related: planet
related: volcano
scope note: combine with other terms

crossCorrelation
type: Concept
alt label: cross correlation
broader: correlation
definition: cross-correlation
pref label: cross-correlation
related: autoCorrelation
related: dataProcessing
related: interferometricCorrelation

crustalDynamics
type: Concept
definition: crustal dynamics
pref label: crustal dynamics
related: Moon
related: crust
related: mantle

crust
type: Concept
definition: crust
pref label: crust
related: Earth
related: Moon
related: crustalDynamics
related: mantle
related: planet
scope note: combine with other terms

cryogenics
type: Concept
definition: cryogenics
pref label: cryogenics
related: cryostat
related: outgassing
related: temperatureControl

cryostat
type: Concept
definition: cryostat
pref label: cryostat
related: cryogenics
related: temperatureControl

Cs
type: Concept
broader: carbonCompound
broader: hydrocarbon
broader: interstellarMolecule
definition: CS molecule
history note: FVH: new (2007-OCT-2)
pref label: CS

curium
type: Concept
alt label: Cm
broader: fundamentalChemicalElement
definition: curium (atomic number 96)
history note: FVH: new (2007-OCT-25)
pref label: curium

current
type: Concept
definition: current
pref label: current
related: antenna
related: currentSheet
related: electricCurrent
scope note: combine with other terms

currentSheet
type: Concept
definition: current sheet
pref label: current sheet
related: antenna
related: current
related: electricCurrent

curveOfGrowth
type: Concept
definition: curve of growth
pref label: curve of growth
related: abundance
related: chemicalElement

cuspCrossing
type: Concept
definition: cusp crossing
history note: FVH: new (2007-OCT-8)
pref label: cusp crossing
related: caustic
related: causticCrossing
related: cusp
related: gravitationalLensing

cusp
type: Concept
definition: cusp
history note: FVH: new (2007-OCT-8)
pref label: cusp
related: causticCrossing
related: cuspCrossing
related: gravitationalLensing

cyanoacetylene
type: Concept
broader: carbonCompound
definition: cyanoacetylene
pref label: cyanoacetylene

cyanodiacetylene
type: Concept
broader: carbonCompound
definition: cyanodiacetylene
pref label: cyanodiacetylene

cyanogen
type: Concept
alt label: CN
broader: carbonCompound
definition: cyanogen
pref label: cyanogen

cyanogenLine
type: Concept
broader: spectralLine
definition: cyanogen line
pref label: cyanogen line
related: absorptionLine

cyanopolyene
type: Concept
broader: carbonCompound
change note: FVH: corrected spelling (2007-OCT-2)
definition: cyanopolyene
pref label: cyanopolyene

cycle
type: Concept
definition: cycle
pref label: cycle
related: period

cyclotronRadiation
type: Concept
broader: electromagneticRadiation
broader: radiation
broader: synchrotronRadiation
definition: cyclotron radiation
pref label: cyclotron radiation
related: radiationMechanism

dampingConstant
type: Concept
definition: damping constant
pref label: damping constant
related: lineFormation
related: radiationDamping
related: radiativeBraking

DanjonAstrolabe
type: Concept
broader: astrolabe
definition: Danjon astrolabe
pref label: Danjon astrolabe

darkAdaption
type: Concept
alt label: retinal adaption
definition: dark adaption
pref label: dark adaption
related: colorVision
related: darkness
related: nightVision
related: vision

darkCloud
type: Concept
broader: interstellarMatter
definition: dark cloud
pref label: dark cloud
related: CIiRegion

darkCurrentCalibration
type: Concept
broader: calibration
definition: dark-current calibration
history note: FVH: new (2007-OCT-3)
pref label: dark-current calibration
related: CcdDetector

DarkEnergy
type: Concept
alt label: dark energy
definition: Dark Energy
history note: FVH: new (2007-SEP-21)
pref label: Dark Energy
related: DarkMatter
related: HubbleLaw
related: coldDarkMatter
related: cosmologicalConstant
related: cosmology
related: earlyUniverse
related: galaxyCount
related: galaxyDistribution
related: generalTheoryOfRelativity
related: redshiftDistanceRelation
related: redshiftMagnitudeRelation
related: spaceTimeCurvature
related: universe

DarkMatter
type: Concept
broader: intergalacticMatter
broader: interstellarMatter
definition: Dark Matter
narrower: baryonicDarkMatter
narrower: coldDarkMatter
pref label: Dark Matter
related: DarkEnergy
related: GalacticRotation
related: cosmology
related: elementaryParticle
related: galaxyRotationCurve
related: massDistribution

darkNebula
type: Concept
alt label: absorption nebula
broader: interstellarMatter
broader: nebula
definition: dark nebula
narrower: BokGlobule
narrower: cometaryGlobule
pref label: dark nebula
related: WolfDiagram
related: globule
related: starFormation

darkness
type: Concept
definition: darkness
pref label: darkness
related: darkAdaption
related: diurnalVariation
related: electromagneticRadiation
related: opticalProperty
related: visibleRadiation

darkroom
type: Concept
definition: darkroom
pref label: darkroom
related: photographicProcessing
related: photography

darmtadtium
type: Concept
alt label: Ds
broader: fundamentalChemicalElement
definition: darmtadtium (atomic number 110)
history note: FVH: new (2007-OCT-25)
pref label: darmtadtium

DaStar
type: Concept
broader: whiteDwarf
change note: FVH: modified from original DA_star (2007-OCT-1)
definition: DA white dwarf star
pref label: DA star
related: DbStar
related: DoStar

dataAcquisition
type: Concept
definition: data acquisition
pref label: data acquisition
related: counter
related: counting
related: dataAnalysis
related: digitalRecorder
related: observation
related: observingTechnique

dataAnalysis
type: Concept
broader: analysis
definition: data analysis
narrower: errorAnalysis
pref label: data analysis
related: dataAcquisition
related: dataProcessing
related: dataReduction
related: dataStorage
related: determination

database
type: Concept
alt label: data base
broader: computing
definition: database
pref label: database
related: dataCenter
related: dataRetrieval
related: dataStorage
related: virtualObservatory

dataCenter
type: Concept
definition: data center
pref label: data center
related: computer
related: dataProcessing
related: dataReduction
related: dataRetrieval
related: dataStorage
related: database
related: onLineSystem
related: virtualObservatory

dataProcessing
type: Concept
broader: computing
definition: data processing
narrower: MonteCarloTechnique
narrower: dataReduction
narrower: numericalAnalysis
pref label: data processing
related: autoCorrelation
related: cleanMethod
related: computer
related: computerProgram
related: crossCorrelation
related: dataAnalysis
related: dataCenter
related: dataRetrieval
related: dataStorage
related: errorAnalysis
related: observingTechnique
related: onLineSystem
related: reductionMethod

dataReduction
type: Concept
broader: dataProcessing
definition: data reduction
pref label: data reduction
related: computer
related: dataAnalysis
related: dataCenter
related: dataRetrieval
related: dataStorage
related: errorAnalysis
related: fineAnalysis
related: reductionMethod

dataRetrieval
type: Concept
broader: computing
definition: data retrieval
pref label: data retrieval
related: dataCenter
related: dataProcessing
related: dataReduction
related: dataStorage
related: database
related: virtualObservatory

dataStorage
type: Concept
broader: computing
definition: data storage
narrower: RaidArray
narrower: analogRecorder
pref label: data storage
related: computer
related: dataAnalysis
related: dataCenter
related: dataProcessing
related: dataReduction
related: dataRetrieval
related: database

DbStar
type: Concept
broader: heliumRichStar
broader: whiteDwarf
definition: DB white dwarf star
history note: FVH: new (2007-OCT-1)
pref label: DB star
related: DaStar
related: DoStar

DdoPhotometry
type: Concept
broader: mediumBandPhotometry
broader: photometricSystem
definition: DDO photometry
pref label: DDO photometry

deadTimeCalibration
type: Concept
broader: calibration
definition: dead-time calibration
history note: FVH: new (2007-OCT-3)
pref label: dead-time calibration

decayOscillation
type: Concept
definition: decay of oscillation
pref label: decay oscillation
related: amplitude
related: oscillation
related: radiationDamping

deceleration
type: Concept
definition: deceleration
pref label: deceleration
related: acceleration
related: decelerationParameter

decelerationParameter
type: Concept
alt label: q-parameter
broader: cosmologicalParameter
definition: deceleration parameter
pref label: deceleration parameter
related: cosmologicalDistanceScale
related: deceleration

Declination
type: Concept
alt label: celestial latitude
broader: equatorialCoordinateSystem
broader: latitude
definition: Declination
pref label: Declination
related: RightAscension
related: celestialEquator
related: equator
related: equatorialZone

deconvolution
type: Concept
definition: deconvolution
pref label: deconvolution
scope note: combine with other terms

defect
type: Concept
definition: defect
pref label: defect
scope note: combine with other terms

deformation
type: Concept
definition: deformation
pref label: deformation
scope note: combine with other terms

degenerateDwarf
type: Concept
broader: degenerateStar
definition: degenerate dwarf star
narrower: whiteDwarf
pref label: degenerate dwarf

degenerateMatter
type: Concept
broader: matter
definition: degenerate matter
narrower: blackHole
narrower: degenerateStar
pref label: degenerate matter

degenerateStar
type: Concept
broader: degenerateMatter
broader: subluminousStar
definition: degenerate star
narrower: degenerateDwarf
narrower: neutronStar
narrower: pulsar
pref label: degenerate star
related: collapsedStar
related: massRadiusRelation

deltaDelphiniStar
type: Concept
broader: deltaScutiStar
broader: pulsatingVariableStar
definition: delta Delphini star
pref label: delta delphini star

deltaScutiStar
type: Concept
alt label: AI Velorum star
broader: multiPeriodicVariableStar
broader: pulsatingVariableStar
broader: shortPeriodVariableStar
definition: delta Scuti star
narrower: deltaDelphiniStar
pref label: delta Scuti star
related: HeIiIonizationZone
related: dwarfCepheid
related: kappaMechanism
related: nonRadialPulsation
related: radialPulsation

denseCloud
type: Concept
broader: interstellarMatter
broader: nebula
definition: dense cloud
pref label: dense cloud

densitometer
type: Concept
broader: measuringInstrument
definition: densitometer
pref label: densitometer
related: densitometry
related: microdensitometer

densitometry
type: Concept
definition: densitometry
pref label: densitometry
related: densitometer

densityBounded
type: Concept
definition: density bounded
pref label: density bounded
related: density

density
type: Concept
alt label: specific gravity
definition: density
narrower: atmosphericDensity
narrower: electronDensity
narrower: energyDensity
narrower: gasDensity
narrower: massDensity
pref label: density
related: RankineHugoniotRelation
related: densityBounded
related: densityDistribution
related: densityFluctuation
related: densityPerturbation
related: densityVariation
related: densityWaveModel

densityDistribution
type: Concept
definition: density distribution
pref label: density distribution
related: density

densityFluctuation
type: Concept
definition: density fluctuation
pref label: density fluctuation
related: density

densityPerturbation
type: Concept
definition: density perturbation
pref label: density perturbation
related: density

densityVariation
type: Concept
definition: density variation
pref label: density variation
related: density

densityWaveModel
type: Concept
definition: density wave model
pref label: density wave model
related: density

descendingNode
type: Concept
broader: node
change note: FVH: moved NODES to BT (2007-OCT-1)
definition: descending node
pref label: descending node

design
type: Concept
definition: design
narrower: engineering
pref label: design
related: research
scope note: combine with other terms

deSitterUniverse
type: Concept
broader: cosmology
definition: de Sitter universe
pref label: de Sitter universe

destruction
type: Concept
definition: destruction
pref label: destruction
scope note: combine with other terms

detachedBinaryStar
type: Concept
broader: binaryStar
definition: detached binary star
narrower: WUrsaeMajorisStar
pref label: detached binary star
related: semiDetachedBinaryStar

detection
type: Concept
definition: detection
narrower: signalDetection
pref label: detection
scope note: combine with other terms

detectorArray
type: Concept
broader: array
definition: detector array
pref label: detector array
related: arrayProcessor

detector
type: Concept
broader: instrument
change note: FVH: added NT SUPERCONDUCTING_TUNNEL_JUNCTION (2007-SEP-21)
definition: detector
narrower: XRayDetector
narrower: dustDetector
narrower: infraredDetector
narrower: multiChannelDetector
narrower: photographicEmulsion
narrower: photomultiplierTube
narrower: radiometer
narrower: superconductingTunnelJunction
narrower: synchronousDetector
narrower: twoDimensionalDetector
narrower: ultravioletDetector
pref label: detector
related: chargeCoupledDevice
related: chargeInjectionDevice
related: chargeTransferDevice
related: limitingMagnitude
related: pixel
related: quantumEfficiency
related: receiver
related: remoteSensing
related: semiconductorDevice
related: sensitivity
related: shotNoise
related: shutter
related: signalDetection
related: telescopeInstrument
scope note: only the broad classes are shown below; specific type will be found under these, or from the hierarchical list

determination
type: Concept
definition: determination
pref label: determination
related: dataAnalysis
related: measurement
related: quantization

deuterium
type: Concept
broader: hydrogen
definition: deuterium, an isotope of hydrogen
pref label: deuterium
related: isotope

DGalaxy
type: Concept
broader: ellipticalGalaxy
broader: galaxy
definition: rotationally symmetric elliptical galaxy (Yerkes classification scheme)
narrower: cDGalaxy
pref label: D galaxy
related: YerkesClassification
related: massiveGalaxy

diagram
type: Concept
definition: diagram
pref label: diagram
scope note: combine with other terms

diameter
type: Concept
broader: dimension
definition: diameter
narrower: angularDiameter
narrower: isophotalDiameter
pref label: diameter
related: BaadeWesselinkMethod
related: occultation
related: surfaceGravity
scope note: combine with other terms

diamondRingEffect
type: Concept
definition: diamond ring effect
pref label: diamond ring effect
related: Sun
related: bailysBead
related: solarEclipse

dichroicMirror
type: Concept
broader: mirror
definition: dichroic mirror
pref label: dichroic mirror
related: opticalFilm
related: opticalFilter

DickeRadiometer
type: Concept
broader: radiometer
definition: Dicke radiometer
pref label: Dicke radiometer

differentialEquation
type: Concept
broader: mathematicalAnalysis
definition: differential equation
pref label: differential equation

differentialImageMotionMonitor
type: Concept
alt label: DIMM
broader: seeingMonitor
definition: differential image-motion monitor
history note: FVH: new (2007-SEP-21)
pref label: differential image motion monitor

differentialRotation
type: Concept
broader: rotation
change note: FVH: added RT Galactic_rotation, RT galaxy_rotation_curve (2007-OCT-5)
definition: differential rotation
pref label: differential rotation
related: GalacticRotation
related: galaxy
related: galaxyRotationCurve
related: globularStarCluster
related: tidalDisruption
related: tidalDistortion

diffraction
type: Concept
definition: diffraction
narrower: XRayDiffraction
pref label: diffraction
related: AiryDisk
related: RayleighCriterion
related: diffractionPatterns
related: interferenceWave
related: shadowBand

diffractionGrating
type: Concept
alt label: grating
broader: opticalComponent
definition: diffraction grating
narrower: VphGrating
narrower: echelleGrating
narrower: objectiveGrating
narrower: reflectionGrating
narrower: transmissionGrating
pref label: diffraction grating
related: gratingSpectrograph
related: grism
related: spectrograph
related: spectrum

diffractionPatterns
type: Concept
definition: diffraction patterns
pref label: diffraction patterns
related: diffraction

diffuseNebula
type: Concept
broader: nebula
definition: diffuse nebula
pref label: diffuse nebula

diffuseRadiation
type: Concept
definition: diffuse radiation
pref label: diffuse radiation
scope note: combine with other terms

diffusion
type: Concept
definition: diffusion
pref label: diffusion
scope note: combine with other terms

digitalImage
type: Concept
broader: image
definition: digital image
pref label: digital image

digitalRecorder
type: Concept
definition: digital recorder
pref label: digital recorder
related: dataAcquisition

dimension
type: Concept
definition: dimension
narrower: diameter
pref label: dimension
scope note: combine with other terms

diodeArray
type: Concept
broader: array
broader: multiChannelDetector
definition: diode array
pref label: diode array
related: reticonArray

diode
type: Concept
broader: electronicEquipment
definition: diode
pref label: diode

dioptricSystem
type: Concept
broader: opticalSystem
definition: dioptric system
pref label: dioptric system
related: lens
related: opticalTelescope

dipoleAntenna
type: Concept
alt label: dipole antennas
broader: antenna
broader: directionalAntenna
definition: dipole antenna
pref label: dipole antenna
related: dipole

dipole
type: Concept
definition: dipole
narrower: halfWaveDipole
pref label: dipole
related: dipoleAntenna
related: electricCharge
related: electricDipole

diracCosmology
type: Concept
broader: cosmology
definition: Dirac cosmology
pref label: dirac cosmology

directionalAntenna
type: Concept
alt label: directional antennas
broader: antenna
definition: directional antenna
narrower: MillsCrossAntenna
narrower: YagiAntenna
narrower: dipoleAntenna
narrower: parabolicAntenna
pref label: directional antenna

dirtySnowballTheory
type: Concept
definition: dirty snowball theory
pref label: dirty snowball theory
related: comet
related: nucleusCelestialObject

discoloration
type: Concept
definition: discoloration
pref label: discoloration
scope note: combine with other terms

discoveries
type: Concept
definition: discoveries
pref label: discoveries
related: research
related: spaceExploration
scope note: combine with other terms

discreteRadioSource
type: Concept
broader: radioSource
definition: discrete radio source
pref label: discrete radio source

dishAntenna
type: Concept
alt label: dish antennas
broader: radioTelescope
definition: dish antenna
pref label: dish antenna
related: antenna
related: parabolicReflector
related: radarTelescope

disintegration
type: Concept
definition: disintegration
pref label: disintegration
scope note: combine with other terms

disk
type: Concept
definition: discs UK
definition: disk
narrower: accretionDisk
narrower: circumstellarDisk
narrower: gaseousDisk
narrower: gravitatingDisk
pref label: disk
related: diskFlaring
related: diskGalaxy
related: diskPopulation
related: diskStar

diskFlaring
type: Concept
definition: disc flaring UK
definition: disk flaring
pref label: disk flaring
related: disk
related: morphology

diskGalaxy
type: Concept
broader: galaxy
definition: disc galaxy UK
definition: disk galaxy
narrower: lenticularGalaxy
narrower: spiralGalaxy
pref label: disk galaxy
related: disk
related: massDistribution

diskPopulation
type: Concept
broader: populationIiStar
definition: disc population UK
definition: disk population
pref label: disk population
related: GalacticPlane
related: disk
related: stellarPopulation

diskStar
type: Concept
broader: populationIiStar
definition: disc star UK
definition: disk star
pref label: disk star
related: GalacticPlane
related: disk
related: gaseousDisk

dispersion
type: Concept
definition: dispersion
pref label: dispersion
scope note: combine with other terms

disruption
type: Concept
definition: disruption
pref label: disruption
scope note: combine with other terms

dissipation
type: Concept
definition: dissipation
pref label: dissipation
scope note: combine with other terms

distance
type: Concept
definition: distance
pref label: distance
related: BodesLaw
related: absoluteMagnitude
related: distanceIndicator
related: distanceMeasurement
related: distanceModulus
related: distanceScale
related: lightYear
related: parallax
related: parsec
related: rangeFinder
related: trigonometricParallax

distanceIndicator
type: Concept
definition: distance indicator
pref label: distance indicator
related: distance
related: distanceMeasurement
related: distanceModulus
related: distanceScale

distanceMeasurement
type: Concept
definition: distance measurement
narrower: CepheidDistance
narrower: FaberJacksonDistance
narrower: RgbTipDistance
narrower: SbfDistance
pref label: distance measurement
related: distance
related: distanceIndicator
related: distanceScale

distanceModulus
type: Concept
alt label: modulus
definition: distance modulus
pref label: distance modulus
related: absoluteMagnitude
related: distance
related: distanceIndicator
related: distanceScale
related: parallax

distanceScale
type: Concept
definition: distance scale
narrower: cosmologicalDistanceScale
pref label: distance scale
related: AstronomicalUnit
related: distance
related: distanceIndicator
related: distanceMeasurement
related: distanceModulus
related: parsec

distortion
type: Concept
broader: opticalAberration
definition: distortion
pref label: distortion
related: astigmatism
related: chromaticAberration
related: comaticAberration
related: fieldCurvature
related: opticalSystem
related: sphericalAberration

distributionFunction
type: Concept
broader: function
definition: distribution function
pref label: distribution function
related: distributionInSpace
related: frequencyDistribution
related: statistics
scope note: in mathematics

distributionInSpace
type: Concept
definition: distribution in space
pref label: distribution in space
related: distributionFunction
scope note: combine with other terms

diurnalParallax
type: Concept
broader: parallax
definition: diurnal parallax
narrower: horizontalParallax
pref label: diurnal parallax
related: zenithDistance

diurnalPhenomena
type: Concept
definition: diurnal phenomena
pref label: diurnal phenomena
related: diurnalVariation

diurnalVariation
type: Concept
definition: diurnal variation
pref label: diurnal variation
related: darkness
related: diurnalPhenomena

DLayer
type: Concept
alt label: D region
definition: D layer
pref label: D layer
related: EarthAtmosphere
related: ionosphere

DLine
type: Concept
broader: spectralLine
definition: D line
pref label: D line
related: absorptionSpectrum

dome
type: Concept
alt label: telescope dome
definition: dome
pref label: dome
related: domeSeeing
related: observatory
related: telescope
related: temperatureControl
related: ventilation
scope note: excluding lunar dome

domeSeeing
type: Concept
broader: seeing
definition: dome seeing
pref label: dome seeing
related: dome
related: ventilation

DopplerBroadening
type: Concept
broader: lineBroadening
definition: Doppler broadening
pref label: Doppler broadening
related: DopplerEffect
related: StarkBroadening
related: ZeemanSplitting
related: lineWidth
related: naturalLineWidth
related: pressureBroadening

DopplerEffect
type: Concept
definition: Doppler effect
narrower: blueshift
narrower: redshift
pref label: Doppler effect
related: DopplerBroadening
related: lineShift
related: radar
related: radialVelocity
related: spectroscopicAnalysis
related: spectroscopicBinaryStar
related: stellarMotion

DoStar
type: Concept
broader: whiteDwarf
definition: DO white dwarf star
history note: FVH: new (2007-OCT-9)
narrower: Pg1159Star
pref label: DO star
related: DaStar
related: DbStar

doubleGalaxy
type: Concept
alt label: binary galaxy
broader: binarySystem
broader: galaxy
definition: double galaxy
pref label: double galaxy
related: companionGalaxy
related: galaxyMerger

doubleModeCepheid
type: Concept
alt label: beat_Cepheid
alt label: double mode Cepheid
broader: Cepheid
broader: doubleModeVariableStar
broader: pulsatingVariableStar
definition: double-mode Cepheid
pref label: double-mode Cepheid
related: doubleModePulsation

doubleModePulsation
type: Concept
alt label: double mode pulsation
broader: multiPeriodicPulsation
definition: double-mode pulsation
pref label: double-mode pulsation
related: doubleModeCepheid
related: doubleModeVariableStar
related: pulsatingVariableStar

doubleModeVariableStar
type: Concept
alt label: double mode variable star
broader: multiPeriodicVariableStar
broader: pulsatingVariableStar
definition: double-mode variable star
narrower: RrLyraeStar
narrower: doubleModeCepheid
pref label: double-mode variable star
related: doubleModePulsation

doubleQuasar
type: Concept
broader: gravitationallyLensedSource
definition: double quasar
pref label: double quasar
related: gravitationalDeflection
related: gravitationalLensing
related: quasar

DqHerculisStar
type: Concept
broader: eclipsingBinaryStar
broader: slowNova
definition: DQ Herculis star
pref label: DQ Herculis star

dredgeUp
type: Concept
definition: dredge up
pref label: dredge up
related: convection
related: giant
related: metalAbundance
related: stellarAtmosphere
related: stellarInterior

driftScan
type: Concept
definition: drift scan
pref label: drift scan
related: photometry
related: radioStructure
related: surfacePhotometry

driftWave
type: Concept
broader: wave
definition: drift wave
pref label: drift wave

drive
type: Concept
definition: drive
pref label: drive
related: coelostat
related: controlSystem
related: siderostat
related: telescope

dubnium
type: Concept
alt label: Db
broader: fundamentalChemicalElement
definition: dubnium (atomic number 105)
history note: FVH: new (2007-OCT-25)
pref label: dubnium

dustCloud
type: Concept
broader: cloud
broader: interstellarMatter
definition: dust cloud
pref label: dust cloud
related: dust
related: interstellarDust

dustDetector
type: Concept
broader: detector
definition: dust detector
pref label: dust detector
related: dust

dust
type: Concept
alt label: cosmic dust
broader: intergalacticMatter
broader: interstellarMatter
definition: dust
narrower: interplanetaryDust
narrower: interstellarDust
narrower: zodiacalDust
pref label: dust
related: comet
related: dustCloud
related: dustDetector
related: dustGrain
related: dustNebula
related: dustShell
related: dustStorm
related: gasToDustRatio

dustGrain
type: Concept
broader: interstellarMatter
definition: dust grain
pref label: dust grain
related: adsorption
related: dust

dustNebula
type: Concept
broader: interstellarMatter
broader: nebula
definition: dust nebula
pref label: dust nebula
related: dust

dustShell
type: Concept
broader: circumstellarShell
broader: shell
definition: dust shell
pref label: dust shell
related: circumstellarDust
related: dust
related: symbioticStar

dustStorm
type: Concept
definition: dust storm
pref label: dust storm
related: dust
related: planet
related: surfaceOfCelestialBody

dwarfCepheid
type: Concept
broader: irregularVariableStar
broader: multiPeriodicVariableStar
broader: pulsatingVariableStar
definition: dwarf Cepheid
pref label: dwarf Cepheid
related: Cepheid
related: deltaScutiStar

dwarf
type: Concept
broader: mainSequenceStar
definition: dwarf star
narrower: ADwarf
narrower: BDwarf
narrower: FDwarf
narrower: GDwarf
narrower: KDwarf
narrower: MDwarf
narrower: ODwarf
narrower: blackDwarf
narrower: flareStar
narrower: lateTypeDwarf
narrower: nearbyDwarf
pref label: dwarf
related: brownDwarf
related: lowLuminosityStar
related: lowMassStar
related: luminosityClassification
related: mainSequence
related: subdwarf
scope note: the term alone refers to main sequence star, but subterms may refer to evolved star

dwarfGalaxy
type: Concept
broader: galaxy
broader: peculiarGalaxy
definition: dwarf galaxy
pref label: dwarf galaxy

dwarfNova
type: Concept
alt label: DN
broader: cataclysmicVariableStar
broader: eruptiveBinaryStar
change note: FVH: total update (2007-SEP-24)
definition: dwarf nova
narrower: SuUrsaeMajorisStar
narrower: SxArietisStar
narrower: UGeminorumStar
narrower: WzSagittaeStar
narrower: ZCamelopardalisStar
pref label: dwarf nova
related: AmCanumVenaticorumStar
related: UvPerseiStar
related: UxUrsaeMajorisStar
related: XRayBinaryStar
related: accretionDisk
related: emissionLineStar

dwarfPlanet
type: Concept
broader: rotatingBody
definition: dwarf planet
narrower: Ceres
narrower: Pluto
pref label: dwarf planet
related: planet

dynamicalEvolution
type: Concept
broader: evolution
definition: dynamical evolution
pref label: dynamical evolution

dynamicalFriction
type: Concept
broader: friction
definition: dynamical friction
pref label: dynamical friction
related: radiativeBraking

dynamicalParallax
type: Concept
broader: parallax
definition: dynamical parallax
pref label: dynamical parallax
related: binaryStar
related: kinematicParallax
related: movingClusterParallax

dynamicalTime
type: Concept
broader: time
definition: dynamical time
pref label: dynamical time

dynamics
type: Concept
definition: dynamics
pref label: dynamics
scope note: combine with other terms

dynamoTheory
type: Concept
definition: dynamo theory
pref label: dynamo theory
related: magneticField

dysprosium
type: Concept
alt label: Dy
broader: fundamentalChemicalElement
broader: rareEarth
definition: dysprosium (atomic number 66)
history note: FVH: new (2007-OCT-25)
pref label: dysprosium

earlyTypeEmissionStar
type: Concept
alt label: early type emission star
broader: emissionLineStar
definition: early-type emission star
narrower: AeStar
narrower: BeStar
narrower: OeStar
narrower: OefStar
narrower: OfStar
narrower: WolfRayetStar
pref label: early-type emission star

earlyTypeGalaxy
type: Concept
alt label: early type galaxy
broader: galaxy
definition: early-type galaxy
pref label: early-type galaxy

earlyTypeStar
type: Concept
alt label: blue star
alt label: early type star
alt label: hot star
broader: ultravioletSource
definition: early-type star
narrower: AStar
narrower: BStar
narrower: OStar
narrower: ObStar
narrower: earlyTypeVariableStar
narrower: faintBlueStar
pref label: early-type star
related: orionPopulationStar
scope note: see also gas

earlyTypeSupergiant
type: Concept
alt label: early type supergiant star
broader: supergiant
definition: early-type supergiant star
narrower: ASupergiant
narrower: BSupergiant
narrower: OSupergiant
narrower: ObSupergiant
pref label: early-type supergiant
related: luminousBlueVariableStar

earlyTypeVariableStar
type: Concept
alt label: early type variable star
broader: earlyTypeStar
definition: early-type variable star
narrower: SDoradusStar
narrower: SxArietisStar
narrower: betaCepheiStar
narrower: luminousBlueVariableStar
pref label: early-type variable star
related: AStar
related: BStar
related: OStar

earlyUniverse
type: Concept
definition: early universe
pref label: early universe
related: BigBangTheory
related: DarkEnergy
related: cosmology

Earth
type: Concept
broader: planet
definition: Earth
pref label: Earth
related: EarthSciences
related: SolarSystem
related: continent
related: core
related: crater
related: crust
related: earthquake
related: geocorona
related: geodesy
related: geoid
related: geomagnetism
related: geophysics
related: glaciology
related: mantle
related: perigee
related: polarCap
related: radiationBelt
related: scintillation
related: seismology
related: siderealTime
related: solarTerrestrialRelation
related: spaceGeodesy
related: topography
related: troposphere
scope note: combine with other terms

EarthAtmosphere
type: Concept
alt label: terrestrial atmosphere
broader: atmosphere
definition: Earth atmosphere
pref label: Earth atmosphere
related: DLayer
related: ELayer
related: FLayer
related: aeronomy
related: atmosphericExtinction
related: atmosphericScattering
related: atmosphericScintillation
related: atmosphericWindow
related: cloud
related: cloudMonitor
related: exosphere
related: ionosphere
related: magnetosphere
related: mesopause
related: mesosphere
related: meteorology
related: noctilucentCloud
related: ozoneLayer
related: scaleHeight
related: scintillation
related: seeing
related: stratopause
related: stratosphere
related: telluricLine
related: thermosphere
related: tropopause
related: troposphere
related: turbulenceEarthAtmosphere
related: twilight
related: upperAtmosphere

EarthMoonSystem
type: Concept
alt label: Earth Moon system
definition: Earth-Moon system
pref label: Earth-Moon system
related: SolarSystem
related: annualEquation
related: equationOfTheCenter
related: lunarTheory
related: tidalFriction
related: twoBodyProblem

EarthOrbit
type: Concept
definition: Earth orbit
pref label: Earth orbit
related: annualEquation
related: aphelion
related: ecliptic
related: eclipticCoordinateSystem
related: eclipticPlane
related: equationOfTime
related: perihelion
related: solarParallax
related: time
related: tropicalYear
related: zodiac

earthquake
type: Concept
definition: earthquake
pref label: earthquake
related: Earth
related: moonquake

EarthRotation
type: Concept
broader: rotation
definition: Earth rotation
pref label: Earth rotation
related: ChandlerWobble
related: astrometry
related: equationOfTheEquinox
related: nutation
related: polarMotion
related: precession
related: time

EarthSciences
type: Concept
broader: scientificField
definition: Earth sciences
narrower: geodesy
narrower: geology
narrower: geophysics
narrower: glaciology
pref label: Earth sciences
related: Earth
related: geophysicalObservatory

Earthshine
type: Concept
definition: Earthshine
pref label: Earthshine
related: Moon

eccentricAnomaly
type: Concept
broader: orbitalAnomaly
definition: eccentric anomaly
pref label: eccentric anomaly

eccentricity
type: Concept
broader: orbitalElement
definition: eccentricity
pref label: eccentricity
related: ellipticalOrbit

echelleGrating
type: Concept
alt label: echelons
broader: diffractionGrating
definition: echelle grating
pref label: echelle grating
related: echelleSpectrum
related: objectiveGrating
related: reflectionGrating
related: spectrograph
related: transmissionGrating

echelleSpectrograph
type: Concept
alt label: echelle spectrometer
broader: spectrograph
definition: echelle spectrograph
pref label: echelle spectrograph
related: CoudeSpectrum
related: echelleSpectrum
related: highResolutionSpectrosopy
related: highResolutionSpectrum

echelleSpectrum
type: Concept
broader: highResolutionSpectrum
broader: spectrum
definition: echelle spectrum
pref label: echelle spectrum
related: echelleGrating
related: echelleSpectrograph

eclipse
type: Concept
definition: eclipse
narrower: annularEclipse
narrower: lunarEclipse
narrower: partialEclipse
narrower: solarEclipse
narrower: totalEclipse
pref label: eclipse
related: eclipsingBinaryStar
related: occultation
related: penumbra
related: transit
related: umbra

eclipsingBinaryStar
type: Concept
alt label: eclipsing star
alt label: eclipsing variable star
alt label: photometric binary star
broader: binaryStar
broader: variableStar
definition: eclipsing binary star
narrower: AlgolVariableStar
narrower: DqHerculisStar
narrower: RCanisMajorisStar
narrower: WUrsaeMajorisStar
narrower: betaLyraeStar
narrower: upsilonSagittariiStar
pref label: eclipsing binary star
related: RocheLobe
related: contactBinaryStar
related: eclipse
related: ellipsoidalVariableStar
related: interactingBinaryStar
related: partialEclipse
related: photometricElement
related: spectroscopicBinaryStar
related: totalEclipse

eclipticCoordinateSystem
type: Concept
broader: celestialCoordinateSystem
definition: ecliptic coordinate system
pref label: ecliptic coordinate system
related: EarthOrbit
related: ecliptic
related: eclipticLatitude
related: eclipticLongitude
related: eclipticPole

ecliptic
type: Concept
definition: ecliptic
pref label: ecliptic
related: EarthOrbit
related: eclipticCoordinateSystem
related: eclipticPlane
related: eclipticPole
related: equinox
related: obliquityOfEcliptic
related: solstice
related: zodiac

eclipticLatitude
type: Concept
broader: latitude
definition: ecliptic latitude
pref label: ecliptic latitude
related: eclipticCoordinateSystem
related: eclipticLongitude
related: eclipticPole

eclipticLongitude
type: Concept
broader: longitude
definition: ecliptic longitude
pref label: ecliptic longitude
related: eclipticCoordinateSystem
related: eclipticLatitude
related: eclipticPole

eclipticPlane
type: Concept
definition: ecliptic plane
pref label: ecliptic plane
related: EarthOrbit
related: ecliptic
related: eclipticPole
related: obliquityOfEcliptic

eclipticPole
type: Concept
broader: pole
definition: ecliptic pole
narrower: NorthEclipticPole
narrower: SouthEclipticPole
pref label: ecliptic pole
related: ecliptic
related: eclipticCoordinateSystem
related: eclipticLatitude
related: eclipticLongitude
related: eclipticPlane

ECorona
type: Concept
alt label: E component
alt label: E-corona
broader: corona
definition: E corona
pref label: E corona

EddingtonLimit
type: Concept
definition: Eddington limit
pref label: Eddington limit
related: gravitationalForce
related: radiationPressure
related: stellarInterior

edgeEffect
type: Concept
definition: edge effect
pref label: edge effect
related: galaxy
related: photography

EdgeworthKuiperBelt
type: Concept
alt label: Kuiper belt
definition: Edgeworth-Kuiper belt
history note: FVH: new (2007-OCT-2)
pref label: Edgeworth-Kuiper belt
related: EdgeworthKuiperBeltObject
related: SolarSystem
related: asteroid
related: transNeptunianObject

EdgeworthKuiperBeltObject
type: Concept
alt label: EKO
alt label: KBO
alt label: Kuiper belt object
broader: transNeptunianObject
definition: Edgeworth-Kuiper belt object
pref label: Edgeworth-Kuiper belt object
related: EdgeworthKuiperBelt

effectiveTemperature
type: Concept
broader: temperature
definition: effective temperature
pref label: effective temperature
related: electromagneticRadiation
related: photometry
related: radiation
related: standardCandle

eFoldingTime
type: Concept
definition: e-folding time
pref label: e-folding time
related: oscillation

EGalaxy
type: Concept
broader: ellipticalGalaxy
definition: elliptical galaxy (Yerkes classification scheme)
history note: FVH: new (2007-OCT-12)
narrower: EpGalaxy
pref label: E galaxy
related: YerkesClassification

EinsteinCoefficient
type: Concept
definition: Einstein coefficient
pref label: Einstein coefficient
related: absorptionCoefficient
related: emissionCoefficient

EinsteinEffect
type: Concept
alt label: Einstein shift
definition: Einstein effect
pref label: Einstein effect
related: gravitationalRedshift

einsteinium
type: Concept
alt label: Es
broader: fundamentalChemicalElement
definition: einsteinium (atomic number 99)
history note: FVH: new (2007-OCT-25)
pref label: einsteinium

EinsteinRing
type: Concept
broader: gravitationallyLensedSource
definition: Einstein ring
pref label: Einstein ring
related: gravitationalDeflection
related: gravitationalLensing

EinsteinUniverse
type: Concept
broader: cosmology
definition: Einstein universe
pref label: Einstein universe

ejecta
type: Concept
definition: ejecta
pref label: ejecta
related: WolfRayetStar
related: crater

ejection
type: Concept
definition: ejection
pref label: ejection
scope note: combine with other terms

elasticity
type: Concept
definition: elasticity
pref label: elasticity
scope note: combine with other terms

ELayer
type: Concept
alt label: E region
definition: E layer
pref label: E layer
related: EarthAtmosphere
related: ionosphere
scope note: refers to Earth atmosphere

electricalProperty
type: Concept
definition: electrical property
pref label: electrical property
related: electricity

electricCharge
type: Concept
definition: electric charge
pref label: electric charge
related: dipole
related: electricity
related: electrostaticWave

electricCurrent
type: Concept
definition: electric current
pref label: electric current
related: current
related: currentSheet
related: electricity

electricDipole
type: Concept
definition: electric dipole
pref label: electric dipole
related: dipole
related: electricity

electricField
type: Concept
definition: electric field
pref label: electric field
related: PaulTrap
related: electricity
related: electrostaticWave
related: force

electricity
type: Concept
definition: electricity
pref label: electricity
related: electricCharge
related: electricCurrent
related: electricDipole
related: electricField
related: electricalProperty

electrode
type: Concept
definition: electrode
narrower: cathode
narrower: photocathode
pref label: electrode
related: imageTube
related: photomultiplierTube

electrodynamics
type: Concept
definition: electrodynamics
narrower: cosmicElectrodynamics
pref label: electrodynamics

electromagnetic
type: Concept
definition: electromagnetic
pref label: electromagnetic
scope note: combine with other terms

electromagneticField
type: Concept
definition: electromagnetic field
pref label: electromagnetic field
related: electromagneticForces
related: fieldEquation
related: quantumFieldTheory
related: radiationField

electromagneticForces
type: Concept
broader: force
definition: electromagnetic forces
pref label: electromagnetic forces
related: electromagneticField

electromagneticInteraction
type: Concept
broader: interaction
definition: electromagnetic interaction
pref label: electromagnetic interaction

electromagneticRadiation
type: Concept
alt label: electromagnetic wave
broader: radiation
broader: wave
change note: FVH+ES: moved radiation to BT, lots of NT and RT from electromagnetic_wave (2007-OCT-8)
definition: electromagnetic radiation
narrower: CerenkovRadiation
narrower: XRayRadiation
narrower: blackBodyRadiation
narrower: bremsstrahlung
narrower: continuumRadiation
narrower: cyclotronRadiation
narrower: gammaRayRadiation
narrower: infraredRadiation
narrower: microwaveRadiation
narrower: millimeterRadiation
narrower: polarizedLight
narrower: polarizedRadiation
narrower: radioRadiation
narrower: submillimeterRadiation
narrower: synchrotronRadiation
narrower: thermalRadiation
narrower: ultravioletRadiation
narrower: visibleRadiation
pref label: electromagnetic radiation
related: PlanckBlackBodyFormula
related: color
related: darkness
related: effectiveTemperature
related: electrostaticWave
related: fluxDensity
related: gravitationalLensing
related: lamp
related: lightAbsorption
related: lightInterference
related: lightPolarization
related: lightScattering
related: luminescence
related: photon
related: radiativeEquilibrium
related: recombinationLine
related: refraction
related: solarConstant
related: wavelength

electromagneticTheory
type: Concept
definition: electromagnetic theory
narrower: cosmicElectrodynamics
pref label: electromagnetic theory

electronBeam
type: Concept
definition: electron beam
narrower: relativisticElectron
pref label: electron beam

electronDensity
type: Concept
broader: density
definition: electron density
pref label: electron density
related: electron

electron
type: Concept
broader: fundamentalParticle
broader: lepton
broader: nuclearRadiation
broader: particle
definition: electron
pref label: electron
related: ComptonEffect
related: ComptonScattering
related: alphaParticle
related: bremsstrahlung
related: electronDensity
related: inverseComptonEffect
related: inverseComptonScattering
related: pairAnnihilation
related: pairProduction
related: photoionization
related: positron
related: radiativeRecombination
related: radioactivity
related: recombination
related: thermionicEmission

electronicCamera
type: Concept
definition: electronic camera
narrower: electronographicCamera
pref label: electronic camera
related: imageTube

electronicEquipment
type: Concept
definition: electronic equipment
narrower: diode
pref label: electronic equipment
related: instrument
related: shotNoise

electronics
type: Concept
definition: electronics
pref label: electronics
scope note: combine with other terms

electronographicCamera
type: Concept
alt label: electrographic camera
broader: electronicCamera
definition: electronographic camera
pref label: electronographic camera

electronPumping
type: Concept
definition: electron pumping
pref label: electron pumping
related: laser
related: maser

electronTemperature
type: Concept
broader: temperature
definition: electron temperature
history note: APM: new (2007-OCT-4)
pref label: electron temperature

electrostaticWave
type: Concept
definition: electrostatic wave
pref label: electrostatic wave
related: electricCharge
related: electricField
related: electromagneticRadiation
related: radiationScattering

elementaryParticle
type: Concept
broader: particle
definition: elementary particle
narrower: antiparticle
narrower: axion
narrower: baryon
narrower: boson
narrower: graviton
narrower: hadron
narrower: lepton
narrower: meson
narrower: neutrino
narrower: neutron
narrower: photon
narrower: pion
narrower: proton
narrower: quark
pref label: elementary particle
related: DarkMatter
related: FeynmanDiagram
related: particleAcceleration
related: particleCreation
related: particleEscape
related: particleInteraction
related: particleProduction
related: plasma
scope note: only the broad classes are shown below; specific type will be found under these, or from the hierarchical list

elementaryParticleScattering
type: Concept
broader: scattering
definition: elementary particle scattering
pref label: elementary particle scattering
related: radiationScattering

elementFormation
type: Concept
alt label: formation of element
definition: element formation
pref label: element formation
related: abundance
related: chemicalElement
related: frozenInElement
related: origin

ellipsoidalVariableStar
type: Concept
alt label: ellipsoidal binary star
alt label: photometric binary star
broader: binaryStar
broader: closeBinaryStar
broader: contactBinaryStar
broader: variableStar
definition: ellipsoidal variable star
narrower: betaLyraeStar
pref label: ellipsoidal variable star
related: eclipsingBinaryStar
related: spectroscopicBinaryStar

ellipticalGalaxy
type: Concept
alt label: e galaxy
broader: galaxy
definition: elliptical galaxy
narrower: DGalaxy
narrower: EGalaxy
narrower: EpGalaxy
narrower: cDGalaxy
narrower: giantEllipticalGalaxy
pref label: elliptical galaxy
related: FaberJacksonRelation
related: SbfDistance
related: fundamentalPlane
related: oblateness

ellipticalOrbit
type: Concept
alt label: eccentric orbit
broader: orbit
broader: periodicOrbit
definition: elliptical orbit
narrower: circularOrbit
pref label: elliptical orbit
related: annualEquation
related: eccentricity
related: equationOfTime
related: hyperbolicOrbit
related: parabolicOrbit

emergingFlux
type: Concept
broader: magneticField
definition: emerging flux
history note: FVH: new (2007-OCT-29)
pref label: emerging flux
related: solarActivity
related: sunspot

emissionCoefficient
type: Concept
definition: emission coefficient
pref label: emission coefficient
related: EinsteinCoefficient

emissionLine
type: Concept
broader: spectralLine
definition: emission line
narrower: CaIiEmissionLine
narrower: XRayLine
narrower: coronalLine
narrower: forbiddenLine
narrower: recombinationLine
pref label: emission line
related: HIiRegion
related: NeumannLine
related: atomicProcess
related: emissionLineGalaxy
related: emissionLineObject
related: emissionLineStar
related: emissionNebula
related: emissionProcess
related: emissionSpectrum
related: flashSpectrum
related: lineFormation
related: lineIdentification
related: lineIntensitite
related: lineProfile
related: lineRatio
related: spectroscopicAnalysis
related: spectrum

emissionLineGalaxy
type: Concept
broader: emissionLineObject
broader: galaxy
broader: peculiarGalaxy
definition: emission line galaxy
narrower: MarkarianGalaxy
narrower: SeyfertNucleus
narrower: linerGalaxy
pref label: emission line galaxy
related: HIiRegion
related: HaroGalaxy
related: SeyfertGalaxy
related: activeGalacticNucleus
related: activeGalaxy
related: emissionLine

emissionLineObject
type: Concept
definition: emission line object
narrower: HIiRegion
narrower: HerbigHaroObject
narrower: emissionLineGalaxy
narrower: emissionLineStar
narrower: emissionNebula
pref label: emission line object
related: emissionLine
scope note: only the broad classes are shown below; specific type will be found under these, or from the hierarchical list

emissionLineStar
type: Concept
broader: activeStar
broader: emissionLineObject
definition: emission line star
narrower: MeStar
narrower: MeVariableStar
narrower: MiraVariableStar
narrower: RvTauriStar
narrower: RwAurigaeStar
narrower: SDoradusStar
narrower: TTauriStar
narrower: XRayStar
narrower: ZAndromedaeStar
narrower: earlyTypeEmissionStar
narrower: flareStar
narrower: flashStar
narrower: gammaCassiopeiaeStar
narrower: symbioticStar
pref label: emission line star
related: PCygniLineProfile
related: UGeminorumStar
related: dwarfNova
related: emissionLine
related: peculiarStar
related: planetaryNebula
scope note: ES: deleted NT shell_star (2007-OCT-8)

emissionNebula
type: Concept
broader: emissionLineObject
broader: gaseousNebula
broader: nebula
definition: emission nebula
narrower: HIiRegion
narrower: HerbigHaroObject
narrower: planetaryNebula
pref label: emission nebula
related: TTauriStar
related: emissionLine

emissionProcess
type: Concept
definition: emission process
pref label: emission process
related: emissionLine
related: emissionSpectrum

emissionSpectrum
type: Concept
broader: lineSpectrum
broader: spectrum
definition: emission spectrum
narrower: CIEmission
narrower: OhEmission
narrower: XRayEmission
narrower: freeBoundEmission
narrower: freeFreeEmission
narrower: infraredEmission
narrower: microwaveEmission
narrower: radioEmission
narrower: thermalEmission
pref label: emission spectrum
related: HIEmission
related: NeumannLine
related: RamanEffect
related: emissionLine
related: emissionProcess
related: lightEmission

emissivity
type: Concept
definition: emissivity
pref label: emissivity
related: blackBodyRadiation
related: radiation
related: temperature

encounter
type: Concept
definition: encounter
narrower: galaxyEncounter
pref label: encounter
related: galaxyMerger
related: gravitationalInteraction
related: stellarDynamics
scope note: generally of star or galaxy

energeticParticle
type: Concept
definition: energetic particle
pref label: energetic particle
related: plasma

energyContent
type: Concept
definition: energy content
pref label: energy content
scope note: combine with other terms

energyDensity
type: Concept
broader: density
definition: energy density
history note: FVH: new (2007-OCT-24)
pref label: energy density
related: OmegaLambda
related: OmegaParameter

energyDistribution
type: Concept
definition: energy distribution
pref label: energy distribution
scope note: combine with other terms

energy
type: Concept
definition: energy
narrower: gravitationalEnergy
narrower: kineticEnergy
narrower: potentialEnergy
pref label: energy
related: flux
related: force
scope note: combine with other terms

energyLevel
type: Concept
definition: energy level
pref label: energy level
related: spectrum

energySource
type: Concept
definition: energy source
pref label: energy source
scope note: combine with other terms

energySpectrum
type: Concept
definition: energy spectrum
pref label: energy spectrum
related: absorptionSpectrum

energyTransfer
type: Concept
alt label: energy transfer
definition: energy-transfer
narrower: heatTransfer
narrower: radiativeTransfer
pref label: energy-transfer
related: adiabaticProcess
related: conduction
related: convection
related: nonLteTransfer
related: radiation
related: thermodynamicEquilibrium
related: thermodynamics

engineering
type: Concept
broader: design
broader: scientificField
definition: engineering
pref label: engineering
scope note: combine with other terms

EnglishMounting
type: Concept
broader: equatorialMounting
definition: English mounting
pref label: English mounting

enrichment
type: Concept
broader: chemicalEvolution
definition: enrichment
history note: ES: new (2007-OCT-8)
pref label: enrichment
related: abundance

enthalpy
type: Concept
definition: enthalpy
pref label: enthalpy
related: thermodynamics

entropy
type: Concept
definition: entropy
pref label: entropy
related: thermodynamics

envelope
type: Concept
definition: envelope
pref label: envelope
related: comet
related: convection
scope note: combine with other terms

EpGalaxy
type: Concept
broader: EGalaxy
broader: ellipticalGalaxy
broader: peculiarGalaxy
broader: radioGalaxy
definition: peculiar elliptical galaxy with dust absorption (modification of Yerkes classification scheme)
pref label: Ep galaxy
related: YerkesClassification

ephemeralActiveRegion
type: Concept
definition: ephemeral active region
pref label: ephemeral active region
related: solarActivity

ephemeris
type: Concept
definition: ephemeris
pref label: ephemeris
related: almanac
related: calendar
related: catalog
related: fundamentalStar
related: nauticalAlmanac
related: time

ephemerisTime
type: Concept
broader: time
definition: ephemeris time
pref label: ephemeris time
related: UniversalTime
related: civilTime
related: meanSolarTime
related: solarDay
related: year

epoch
type: Concept
definition: epoch
narrower: BesselianEpoch
narrower: JulianEpoch
pref label: epoch
related: JulianDate
related: time

eProcess
type: Concept
definition: e process
pref label: e-process
related: nuclearFusion
related: stellarEvolution
related: supernova

equationOfState
type: Concept
definition: equation of state
history note: FVH: new (2007-OCT-8)
pref label: equation of state
related: atomicProcess
related: interaction

equationOfTheCenter
type: Concept
definition: equation of the center
pref label: equation of the center
related: EarthMoonSystem
related: Moon

equationOfTheEquinox
type: Concept
definition: equation of the equinox
pref label: equation of the equinox
related: EarthRotation
related: equationOfTime
related: equinoxPosition
related: nutation
related: precession
related: siderealTime

equationOfTime
type: Concept
definition: equation of time
pref label: equation of time
related: EarthOrbit
related: ellipticalOrbit
related: equationOfTheEquinox
related: meanSolarTime

equatorCorrection
type: Concept
definition: equator correction
pref label: equator correction
related: celestialEquator

equatorDetermination
type: Concept
definition: equator determination
pref label: equator determination
related: celestialEquator

equator
type: Concept
definition: equator
pref label: equator
related: Declination
related: RightAscension
related: celestialPole
scope note: of Earth; also see celestial equator

equatorialBulge
type: Concept
definition: equatorial bulge
pref label: equatorial bulge
related: geoid
related: oblateness
related: planet
related: rotation

equatorialCoordinateSystem
type: Concept
alt label: celestial coordinate
alt label: equatorial system
broader: celestialCoordinateSystem
definition: equatorial coordinate system
narrower: Declination
narrower: RightAscension
narrower: celestialEquator
narrower: celestialPole
pref label: equatorial coordinate system
related: equatorialMounting
related: equatorialZone

equatorialMounting
type: Concept
broader: telescopeMounting
definition: equatorial mounting
narrower: EnglishMounting
narrower: GermanMounting
narrower: forkMounting
narrower: horseshoeMounting
narrower: yokeMounting
pref label: equatorial mounting
related: altazimuthMounting
related: equatorialCoordinateSystem

equatorialZone
type: Concept
definition: equatorial zone
pref label: equatorial zone
related: Declination
related: equatorialCoordinateSystem

equatorPosition
type: Concept
definition: equator position
pref label: equator position
related: astrometry
related: celestialEquator

equilibrium
type: Concept
definition: equilibrium
pref label: equilibrium
scope note: combine with other terms

equilibriumFigures
type: Concept
definition: equilibrium figures
pref label: equilibrium figures
related: model

equinoxCorrection
type: Concept
definition: equinox correction
pref label: equinox correction
related: equinoxPosition

equinox
type: Concept
definition: equinox
narrower: autumnalEquinox
narrower: meanEquinox
narrower: vernalEquinox
pref label: equinox
related: celestialEquator
related: ecliptic
related: solstice

equinoxPosition
type: Concept
definition: equinox position
pref label: equinox position
related: equationOfTheEquinox
related: equinoxCorrection

equipotentialSurface
type: Concept
definition: equipotential surface
pref label: equipotential surface
related: contactBinaryStar

equivalentWidth
type: Concept
broader: lineWidth
definition: equivalent width
pref label: equivalent width
related: absorption
related: instrumentalProfile
related: lineBroadening
related: spectralLine
related: spectrum

erbium
type: Concept
alt label: Er
broader: fundamentalChemicalElement
broader: rareEarth
definition: erbium (atomic number 68)
history note: FVH: new (2007-OCT-25)
pref label: erbium

eRegion
type: Concept
broader: KapteynSelectedArea
definition: e region
pref label: e region
related: JohnsonPhotometry
related: StromgrenPhotometry
related: photometry

ergosphere
type: Concept
definition: ergosphere
pref label: ergosphere
related: blackHole
related: eventHorizon
related: velocityOfLight

errorAnalysis
type: Concept
broader: dataAnalysis
definition: error analysis
pref label: error analysis
related: dataProcessing
related: dataReduction

error
type: Concept
definition: error
narrower: selectionEffect
pref label: error
related: correction
scope note: combine with other terms

eruption
type: Concept
definition: eruption
pref label: eruption
related: cataclysmicVariableStar
related: eruptiveBinaryStar

eruptiveBinaryStar
type: Concept
broader: binaryStar
definition: eruptive binary star
narrower: SxArietisStar
narrower: XRayBinaryStar
narrower: alpha2CanumVenaticorumStar
narrower: cataclysmicVariableStar
narrower: dwarfNova
narrower: nova
narrower: symbioticStar
pref label: eruptive binary star
related: XRaySource
related: eruption
related: interactingBinaryStar
related: massExchange
related: massLoss

escapeVelocity
type: Concept
broader: velocity
definition: escape velocity
pref label: escape velocity
related: orbitalVelocity
related: parabolicVelocity

ethane
type: Concept
broader: hydrocarbon
definition: ethane
pref label: ethane

ethylene
type: Concept
broader: hydrocarbon
definition: ethylene
pref label: ethylene

europium
type: Concept
alt label: Eu
broader: fundamentalChemicalElement
broader: rareEarth
definition: europium (atomic number 63)
history note: FVH: new (2007-OCT-25)
pref label: europium

evaporation
type: Concept
definition: evaporation
pref label: evaporation
scope note: combine with other terms

eventHorizon
type: Concept
definition: event horizon
pref label: event horizon
related: HawkingRadiation
related: blackHole
related: ergosphere
related: velocityOfLight

EvershedEffect
type: Concept
alt label: Evershed effect
definition: Evershed-effect
pref label: Evershed-effect
related: sunspot

evolutionaryTrack
type: Concept
definition: evolutionary track
narrower: HayashiTrack
narrower: HenyeyTrack
pref label: evolutionary track
related: HertzsprungRussellDiagram
related: stellarEvolution

evolution
type: Concept
definition: evolution
narrower: dynamicalEvolution
narrower: stellarEvolution
pref label: evolution
related: galaxy
related: planet
scope note: combine with other terms

evolvedStar
type: Concept
broader: nonMainSequenceStar
broader: star
definition: evolved star
narrower: horizontalBranchStar
narrower: oldStar
narrower: planetaryNebula
narrower: postMainSequenceStar
narrower: pulsar
narrower: whiteDwarf
pref label: evolved star
related: redGiantTip
scope note: only the broad classes are shown below; specific type will be found under these, or from the hierarchical list

excitation
type: Concept
definition: excitation
pref label: excitation
related: atomicProcess
scope note: combine with other terms

excitingStar
type: Concept
definition: exciting star
pref label: exciting star
related: HIiRegion
related: planetaryNebula

exosphere
type: Concept
definition: exosphere
pref label: exosphere
related: EarthAtmosphere
related: ionosphere
related: magnetosphere
related: planet
related: thermosphere
related: troposphere
related: upperAtmosphere

expandingEnvelope
type: Concept
broader: circumstellarEnvelope
definition: expanding envelope
pref label: expanding envelope
related: circumstellarMatter

expandingUniverse
type: Concept
broader: cosmology
definition: expanding universe
pref label: expanding universe

expansion
type: Concept
definition: expansion
pref label: expansion
scope note: combine with other terms

explosion
type: Concept
definition: explosion
pref label: explosion
scope note: combine with other terms

exponentialProfile
type: Concept
broader: massDistribution
definition: exponential mass-profile
history note: FVH: new (2007-OCT-5)
pref label: exponential profile
related: BurkertProfile
related: NavarroFrenkWhiteProfile
related: isothermalSphere

extendedObject
type: Concept
definition: extended object
pref label: extended object
related: extendedSource
related: threeDimensionalSpectrum
related: twoDimensionalSpectrum

extendedSource
type: Concept
broader: radioSource
broader: source
definition: extended source
pref label: extended source
related: extendedObject
related: radioStructure

extragalacticObject
type: Concept
definition: extragalactic object
narrower: extragalacticRadioSource
narrower: galaxy
narrower: quasar
pref label: extragalactic object
scope note: only the broad classes are shown below; specific type will be found under these, or from the hierarchical list

extragalacticRadioSource
type: Concept
broader: extragalacticObject
broader: radioSource
definition: extragalactic radio source
narrower: BlLacertaeObject
narrower: quasar
narrower: radioGalaxy
pref label: extragalactic radio source

extrasolarPlanet
type: Concept
broader: planet
definition: extrasolar planet
pref label: extrasolar planet
related: SolarSystem
related: starFormation

extraterrestrialIntelligence
type: Concept
broader: extraterrestrialLife
change note: FVH: moved EXTRATERRESTRIAL_LIFE to BT (2007-OCT-1)
definition: extraterrestrial intelligence
pref label: extraterrestrial intelligence
related: searchForExtraterrestrialLife

extraterrestrialLife
type: Concept
broader: life
change note: FVH: moved LIFE to BT, SETI to RT (2007-OCT-4)
definition: extraterrestrial life
narrower: extraterrestrialIntelligence
pref label: extraterrestrial life
related: astrobiology
related: interstellarCommunication
related: searchForExtraterrestrialLife

extremeCarbonStar
type: Concept
broader: giant
broader: infraredSource
definition: extreme carbon star
pref label: extreme carbon star
related: circumstellarShell

extremeHorizontalBranchStar
type: Concept
broader: horizontalBranchStar
definition: extreme horizontal branch star
history note: ES: new (2007-OCT-8)
pref label: extreme horizontal branch star

extremePopulationIStar
type: Concept
broader: populationIStar
definition: extreme population I star
pref label: extreme population I star

extremeUltravioletRadiation
type: Concept
alt label: EUV
broader: ultravioletRadiation
definition: extreme ultraviolet radiation
pref label: extreme ultraviolet radiation
related: farUltravioletRadiation
related: nearUltravioletRadiation

eyepiece
type: Concept
definition: eyepiece
narrower: KellnerEyepiece
narrower: RamsdenEyepiece
narrower: orthoscopicEyepiece
pref label: eyepiece
related: graticule
related: lens
related: opticalTelescope
related: reticle

FaberJacksonDistance
type: Concept
broader: distanceMeasurement
definition: Faber-Jackson distance
history note: ES: new (2007-OCT-8)
pref label: Faber-Jackson distance
related: FaberJacksonRelation

FaberJacksonRelation
type: Concept
broader: fundamentalPlane
broader: luminosityDispersionRelation
broader: statisticalRelation
definition: Faber-Jackson relation
history note: FVH: new (2007-OCT-9)
pref label: Faber-Jackson relation
related: FaberJacksonDistance
related: ellipticalGalaxy

FabryPerotInterferometer
type: Concept
alt label: Fabry Perot interferometer
broader: interferometer
definition: Fabry-Perot interferometer
pref label: Fabry-Perot interferometer

FabryPerotSpectrograph
type: Concept
alt label: Fabry Perot spectrograph
alt label: Fabry Perot spectrometer
alt label: Fabry-Perot spectrometer
broader: spectrograph
definition: Fabry-Perot spectrograph
pref label: Fabry-Perot spectrograph

facula
type: Concept
definition: facula
pref label: facula
related: chromosphere
related: granulation
related: photosphere
related: plage

faintBlueStar
type: Concept
broader: earlyTypeStar
broader: faintStar
definition: faint blue star
pref label: faint blue star

faintGalaxy
type: Concept
broader: galaxy
definition: faint galaxy
pref label: faint galaxy
scope note: combine with other terms

faintStar
type: Concept
broader: star
definition: faint star
narrower: faintBlueStar
pref label: faint star
scope note: combine with other terms

falseColorPhotography
type: Concept
broader: photography
definition: false color photography
pref label: false color photography

FanaroffRileyClass
type: Concept
definition: fanaroff riley class
pref label: Fanaroff-Riley class
related: galaxy
related: radioGalaxy

FaradayEffect
type: Concept
broader: magnetoOpticalEffect
definition: Faraday effect
definition: Faraday rotation
pref label: Faraday effect
related: HIiRegion
related: lightPolarization
related: polarizedRadiation

farInfraredRadiation
type: Concept
broader: infraredRadiation
definition: far infrared radiation
pref label: far infrared radiation
related: MMagnitude
related: NMagnitude
related: OMagnitude
related: PMagnitude
related: QMagnitude
related: infraredPhotometry
related: nearInfraredRadiation

farUltravioletRadiation
type: Concept
alt label: FUV
broader: ultravioletRadiation
definition: far ultraviolet radiation
pref label: far ultraviolet radiation
related: extremeUltravioletRadiation
related: nearUltravioletRadiation

fastFourierTransform
type: Concept
alt label: FFT
broader: FourierTransform
definition: fast Fourier transform
pref label: fast Fourier transform

fastNova
type: Concept
broader: nova
definition: fast nova
pref label: fast nova
related: recurrentNova
related: slowNova

FCorona
type: Concept
alt label: F component
alt label: F-corona
broader: corona
definition: F corona
pref label: F corona
related: zodiacalLight

FDwarf
type: Concept
broader: FStar
broader: dwarf
definition: F dwarf star
pref label: F dwarf

feed
type: Concept
definition: feed
pref label: feed
related: feedHorn
related: telescopeInstrument

feedHorn
type: Concept
definition: feed horn
pref label: feed horn
related: antenna
related: feed
related: hornAntenna
related: radioTelescope
related: telescopeInstrument

FermiDiracNucleus
type: Concept
alt label: Fermi Dirac nucleus
broader: nucleusAtom
definition: Fermi-Dirac nucleus
pref label: Fermi-Dirac nucleus
related: BoseEinsteinNucleus
related: FermiDiracStatistics

FermiDiracStatistics
type: Concept
alt label: Fermi Dirac statistics
definition: Fermi-Dirac statistics
pref label: Fermi-Dirac statistics
related: BoseEinsteinStatistics
related: FermiDiracNucleus
related: quantumMechanics

FermiInteraction
type: Concept
broader: weakInteraction
definition: Fermi interaction
pref label: Fermi interaction

fermion
type: Concept
broader: fundamentalParticle
definition: fermion
pref label: fermion
related: boson

fermium
type: Concept
alt label: Fm
broader: fundamentalChemicalElement
definition: fermium (atomic number 100)
history note: FVH: new (2007-OCT-25)
pref label: fermium

FeynmanDiagram
type: Concept
definition: Feynman diagram
pref label: Feynman diagram
related: elementaryParticle

FeynmanIntegrals
type: Concept
definition: Feynman integrals
pref label: Feynman integrals

FGiant
type: Concept
broader: FStar
broader: giant
definition: F giant star
pref label: F giant

fiberOptics
type: Concept
broader: optics
definition: fiber optics
pref label: fiber optics
related: opticalFiber

fibrill
type: Concept
definition: fibrill
pref label: fibrill
related: chromosphere

fieldCorrector
type: Concept
alt label: correcting lens
broader: lens
broader: opticalComponent
definition: field corrector
pref label: field corrector
related: catadioptricSystem
related: correctorPlate
related: focalReducer
related: opticalInstrument

fieldCurvature
type: Concept
alt label: curvature of field
broader: opticalAberration
definition: field curvature
pref label: field curvature
related: astigmatism
related: chromaticAberration
related: comaticAberration
related: distortion
related: opticalSystem
related: sphericalAberration

fieldEquation
type: Concept
definition: field equation
pref label: field equation
related: electromagneticField
related: relativity

fieldGalaxy
type: Concept
broader: galaxy
definition: field galaxy
pref label: field galaxy
scope note: generally, foreground or background object

fieldOfView
type: Concept
definition: field of view
pref label: field of view
related: vignetting
scope note: at telescope' foci

fieldStar
type: Concept
broader: source
broader: star
definition: field star
pref label: field star
scope note: generally, foreground or background object

figuring
type: Concept
broader: polishing
definition: figuring
pref label: figuring
related: HartmannTest
related: lens
related: mirror
related: opticalSurface
related: opticalTesting
scope note: polishing optics to accurate shape

filamentaryNebula
type: Concept
broader: nebula
definition: filamentary nebula
pref label: filamentary nebula
related: nebularFilament

fillingFactor
type: Concept
definition: filling factor
pref label: filling factor
related: telescopeArray

filter
type: Concept
change note: FVH: added NT NEUTRAL_DENSITY_FILTERS (2007-SEP-21)
definition: filter
narrower: interferenceFilter
narrower: neutralDensityFilter
narrower: opticalFilter
pref label: filter
related: attenuation
related: filterWheel

filterWheel
type: Concept
definition: filter wheel
history note: FVH: new (2007-SEP-21)
pref label: filter wheel
related: camera
related: filter

findingChart
type: Concept
definition: finding chart
pref label: finding chart
related: atlas
related: map
related: skySurvey
related: starAtlas

findingList
type: Concept
definition: finding list
pref label: finding list
related: catalog

fineAnalysis
type: Concept
broader: analysis
definition: fine analysis
pref label: fine analysis
related: dataReduction

fineStructure
type: Concept
definition: fine structure
pref label: fine structure
related: molecularLine
related: spectralLine

fireball
type: Concept
broader: meteor
definition: fireball
pref label: fireball
related: bolide

fission
type: Concept
definition: fission
narrower: nuclearFission
pref label: fission

FkCatalogSystem
type: Concept
definition: FK catalog system
pref label: FK catalog system
related: catalog

flare
type: Concept
alt label: chromospheric eruption
definition: flare
narrower: XRayFlare
narrower: opticalFlare
narrower: outburst
narrower: radioFlare
pref label: flare
related: Sun
related: activeSun
related: burst
related: prominence
related: solarActivity
related: solarFilament

flareStar
type: Concept
broader: dwarf
broader: emissionLineStar
broader: infraredSource
broader: radioStar
definition: flare star
narrower: ByDraconisStar
narrower: UvCetiStar
narrower: redDwarfFlareStar
pref label: flare star
related: TAssociation
related: flashStar
related: opticalFlare
related: opticalOutburst
related: radioFlare

flashSpectrum
type: Concept
definition: flash spectrum
pref label: flash spectrum
related: chromosphere
related: emissionLine
related: solarEclipse

flashStar
type: Concept
broader: emissionLineStar
broader: preMainSequenceStar
definition: flash star
pref label: flash star
related: TAssociation
related: UvCetiStar
related: flareStar

flatField
type: Concept
definition: flat field
pref label: flat field
related: imageProcessing
related: twoDimensionalDetector

flatFieldLamp
type: Concept
broader: lamp
definition: flat field lamp
history note: FVH: new (2007-SEP-21)
pref label: flat field lamp
related: calibration
related: camera
related: spectrograph

flattening
type: Concept
definition: flattening
pref label: flattening
scope note: combine with other terms

FLayer
type: Concept
alt label: F region
definition: F layer
pref label: F layer
related: EarthAtmosphere
related: ionosphere
scope note: Earth upper atmosphere

flexure
type: Concept
definition: flexure
pref label: flexure
scope note: combine with other terms

florine
type: Concept
alt label: F
broader: fundamentalChemicalElement
definition: florine (atomic number 9)
history note: FVH: new (2007-OCT-25)
pref label: florine

flow
type: Concept
definition: flow
narrower: nonEquilibriumFlow
pref label: flow
related: fluidDynamics
scope note: combine with other terms

flowInstability
type: Concept
definition: flow instability
pref label: flow instability
related: nonEquilibriumFlow

fluctuation
type: Concept
definition: fluctuation
pref label: fluctuation
scope note: combine with other terms

fluidDynamics
type: Concept
broader: fluidMechanics
definition: fluid dynamics
narrower: gasDynamics
narrower: hydrodynamics
narrower: relativisticFluidDynamics
pref label: fluid dynamics
related: flow
related: massTransfer

fluidMechanics
type: Concept
broader: scientificField
definition: fluid mechanics
narrower: fluidDynamics
pref label: fluid mechanics
related: RayleighTaylorInstability

fluorescence
type: Concept
definition: fluorescence
narrower: XRayFluorescence
pref label: fluorescence
related: luminescence
related: photoluminescence
related: spectrum

fluxDensity
type: Concept
definition: flux density
pref label: flux density
related: electromagneticRadiation
related: luminosity
related: radiation

flux
type: Concept
definition: flux
pref label: flux
related: energy
related: luminosity
scope note: combine with other terms

focalLength
type: Concept
definition: focal length
pref label: focal length
related: focalReducer
related: focus

focalReducer
type: Concept
definition: focal reducer
pref label: focal reducer
related: fieldCorrector
related: focalLength

focus
type: Concept
definition: focus
narrower: CassegrainFocus
narrower: CoudeFocus
narrower: NasmythFocus
narrower: NewtonianFocus
narrower: primeFocus
pref label: focus
related: focalLength
related: opticalAberration
related: telescope

FokkerPlanckEquation
type: Concept
alt label: Fokker Planck equation
definition: Fokker-Planck equation
pref label: Fokker-Planck equation
related: stellarDynamics

forbiddenLine
type: Concept
broader: emissionLine
definition: forbidden line
pref label: forbidden line
related: forbiddenTransition
related: nebula
related: spectrum

forbiddenTransition
type: Concept
definition: forbidden transition
pref label: forbidden transition
related: forbiddenLine
related: nebula
related: spectrum

forbushEffect
type: Concept
definition: forbush effect
pref label: forbush effect
related: cosmicRay
related: solarPhysics

force
type: Concept
definition: force
narrower: centrifugalForce
narrower: centripetalForce
narrower: electromagneticForces
narrower: gravitationalForce
pref label: force
related: electricField
related: energy
related: magneticField
scope note: combine with other terms

forecasts
type: Concept
definition: forecasts
pref label: forecasts
related: prediction
scope note: combine with other terms

forkMounting
type: Concept
broader: equatorialMounting
definition: fork mounting
pref label: fork mounting

formation
type: Concept
definition: formation
pref label: formation
scope note: combine with other terms

FourierAnalysis
type: Concept
alt label: harmonic analysis
definition: Fourier analysis
pref label: Fourier analysis
related: FourierComponent
related: FourierTransform
related: fundamentalFrequency
related: harmonicFrequency
related: maximumEntropyMethod
related: multiPeriodicPulsation
related: overtoneFrequency
related: waveformAnalysis

FourierComponent
type: Concept
definition: Fourier component
pref label: Fourier component
related: FourierAnalysis
related: harmonicFrequency

FourierSpectrograph
type: Concept
alt label: Fourier spectrometer
broader: spectrograph
definition: Fourier spectrograph
pref label: Fourier spectrograph

FourierTransform
type: Concept
definition: Fourier transform
narrower: fastFourierTransform
pref label: Fourier transform
related: FourierAnalysis

FourierTransformSpectroscopy
type: Concept
broader: spectroscopy
definition: Fourier transform spectroscopy
pref label: Fourier transform spectroscopy

fragmentation
type: Concept
definition: fragmentation
pref label: fragmentation
scope note: combine with other terms

fragment
type: Concept
definition: fragment
pref label: fragment
scope note: combine with other terms

francium
type: Concept
alt label: Fr
broader: fundamentalChemicalElement
definition: francium (atomic number 87)
history note: FVH: new (2007-OCT-25)
pref label: francium

FraunhoferLine
type: Concept
broader: spectralLine
definition: Fraunhofer line
narrower: BBand
narrower: GBand
narrower: HLine
narrower: KLine
pref label: Fraunhofer line
related: Sun
related: absorptionSpectrum
scope note: not a complete list of terms

freeBoundEmission
type: Concept
alt label: free bound emission
broader: emissionSpectrum
broader: radiationMechanism
definition: free-bound emission
pref label: free-bound emission

freeFreeEmission
type: Concept
alt label: free free emission
broader: emissionSpectrum
broader: radiationMechanism
definition: free-free emission
pref label: free-free emission
related: spectrum
related: thermalEmission

fRegion
type: Concept
broader: KapteynSelectedArea
definition: f region
pref label: f region
related: JohnsonPhotometry
related: StromgrenPhotometry
related: photometry

frequencyAnalysis
type: Concept
definition: frequency analysis
pref label: frequency analysis
related: maximumEntropyMethod
related: multiPeriodicPulsation

frequencyDistribution
type: Concept
definition: frequency distribution
pref label: frequency distribution
related: HessDiagram
related: distributionFunction

frequency
type: Concept
definition: frequency
pref label: frequency
related: wavelength
scope note: combine with other terms

frequencyShift
type: Concept
definition: frequency shift
narrower: glitch
pref label: frequency shift
related: blueshift
related: pulsar
related: redshift

frequencyStandard
type: Concept
definition: frequency standard
pref label: frequency standard
related: instrument

friction
type: Concept
definition: friction
narrower: dynamicalFriction
pref label: friction

FriedmannUniverse
type: Concept
broader: cosmology
definition: Friedmann universe
pref label: Friedmann universe
related: BigBangTheory
related: oscillatingUniverse

frozenInElement
type: Concept
definition: frozen in element
pref label: frozen in element
related: elementFormation
related: supernova

FStar
type: Concept
broader: intermediateTypeStar
definition: F star
narrower: FDwarf
narrower: FGiant
narrower: FSubdwarf
narrower: FSubgiant
narrower: FSupergiant
pref label: F star
related: spectralType

FSubdwarf
type: Concept
broader: FStar
broader: subdwarf
definition: F subdwarf star
pref label: F subdwarf

FSubgiant
type: Concept
broader: FStar
broader: subgiant
definition: F subgiant star
pref label: F subgiant

FSupergiant
type: Concept
broader: FStar
broader: supergiant
definition: F supergiant star
narrower: UuHerculisStar
pref label: F supergiant

function
type: Concept
definition: function
narrower: distributionFunction
pref label: function
scope note: in mathematics

fundamentalChemicalElement
type: Concept
broader: atom
broader: chemicalElement
definition: the fundamental chemical element which appear in the periodic table
history note: FVH: new (2007-OCT-25)
narrower: actinium
narrower: aluminum
narrower: americium
narrower: antimony
narrower: argon
narrower: arsenic
narrower: astatine
narrower: barium
narrower: berkelium
narrower: beryllium
narrower: bismuth
narrower: bohrium
narrower: boron
narrower: bromine
narrower: cadmium
narrower: caesium
narrower: calcium
narrower: californium
narrower: carbon
narrower: cerium
narrower: chlorine
narrower: chromium
narrower: cobalt
narrower: copper
narrower: curium
narrower: darmtadtium
narrower: dubnium
narrower: dysprosium
narrower: einsteinium
narrower: erbium
narrower: europium
narrower: fermium
narrower: florine
narrower: francium
narrower: gadolinium
narrower: gallium
narrower: germanium
narrower: gold
narrower: hafnium
narrower: hassium
narrower: helium
narrower: holmium
narrower: hydrogen
narrower: indium
narrower: iodine
narrower: iridium
narrower: iron
narrower: krypton
narrower: lanthanum
narrower: lawrencium
narrower: lead
narrower: lithium
narrower: lutetium
narrower: magnesium
narrower: manganese
narrower: meitnerium
narrower: mendelevium
narrower: mercury
narrower: molybdenum
narrower: neodymium
narrower: neon
narrower: neptunium
narrower: nickel
narrower: niobium
narrower: nitrogen
narrower: nobelium
narrower: osmium
narrower: oxygen
narrower: palladium
narrower: phosphorus
narrower: platinum
narrower: plutonium
narrower: polonium
narrower: potassium
narrower: praseodymium

fundamentalFrequency
type: Concept
definition: fundamental frequency
pref label: fundamental frequency
related: FourierAnalysis
related: fundamentalMode
related: harmonicFrequency
related: overtoneFrequency
related: variableStar

fundamentalMode
type: Concept
broader: pulsationMode
definition: fundamental mode
pref label: fundamental mode
related: fundamentalFrequency
related: overtoneMode

fundamentalParticle
type: Concept
broader: particle
definition: fundamental particle
narrower: electron
narrower: fermion
narrower: neutron
narrower: proton
pref label: fundamental particle

fundamentalPlane
type: Concept
broader: luminosityDispersionRelation
broader: radiusLuminosityRelation
definition: fundamental plane
history note: FVH: new (2007-OCT-9)
narrower: FaberJacksonRelation
pref label: fundamental plane
related: ellipticalGalaxy

fundamentalStar
type: Concept
broader: star
definition: fundamental star
pref label: fundamental star
related: astrometry
related: catalog
related: ephemeris

fundamentalSystem
type: Concept
definition: fundamental system
pref label: fundamental system
related: position
scope note: combine with other terms

funneling
type: Concept
definition: funneling
pref label: funneling
related: lateTypeGiant
related: stellarEvolution

FuOrionisStar
type: Concept
broader: TTauriStar
broader: infraredSource
definition: fu orionis star
pref label: FU Orionis star
related: TAssociation
related: massLoss

fusion
type: Concept
definition: fusion
narrower: nuclearFusion
pref label: fusion

futureLightCone
type: Concept
broader: lightCone
definition: future light cone
pref label: future light cone
related: pastLightCone

gadolinium
type: Concept
alt label: Gd
broader: fundamentalChemicalElement
broader: rareEarth
definition: gadolinium (atomic number 64)
history note: FVH: new (2007-OCT-25)
pref label: gadolinium

Galactic
type: Concept
definition: Galactic
pref label: Galactic
scope note: FVH: WARNING: usage is not consistent when combined within tokens, e.g. galactic_nucleus (the MW has only one!), so capitalized (2007-OCT-5)
scope note: IAU: used as an adjective only for Milky Way property see also galaxy

GalacticAnticenter
type: Concept
alt label: anticenter
change note: FVH: capitalized, since only refers to MW (2007-OCT-5)
definition: Galactic anticenter
pref label: Galactic anticenter
related: GalacticCoordinateSystem
related: MilkyWayGalaxy

GalacticBulge
type: Concept
broader: bulge
change note: FVH: capitalized, since only refers to MW; added BT bulge (2007-OCT-5)
definition: Galactic bulge (Milky Way)
pref label: Galactic bulge
related: GalacticCenter
related: GalacticPlane
related: GalacticStructure
related: MilkyWayGalaxy

GalacticCenter
type: Concept
broader: galacticNucleus
change note: FVH: capitalized, since only refers to MW; added BT galactic_nucleus (2007-OCT-5)
definition: Galactic center (Milky Way)
pref label: Galactic center
related: GalacticBulge
related: GalacticCoordinateSystem
related: GalacticStructure
related: MilkyWayGalaxy

GalacticCluster
type: Concept
broader: openStarCluster
change note: FVH: capitalized, since only refers to MW (2007-OCT-5)
definition: Galactic open star cluster (in Milky Way)
pref label: Galactic cluster
related: MilkyWayGalaxy

GalacticCoordinateSystem
type: Concept
broader: celestialCoordinateSystem
change note: FVH: capitalized, since only refers to MW (2007-OCT-5)
definition: Galactic coordinate system
pref label: Galactic coordinate system
related: GalacticAnticenter
related: GalacticCenter
related: GalacticLatitude
related: GalacticLongitude
related: GalacticPole
related: MilkyWayGalaxy

GalacticCosmicRay
type: Concept
broader: cosmicRay
change note: FVH: capitalized, since only refers to MW; moved cosmic_ray to BT (2007-OCT-5)
definition: Galactic cosmic ray
pref label: Galactic cosmic ray
related: MilkyWayGalaxy

GalacticEquator
type: Concept
change note: FVH: capitalized, since only refers to MW (2007-OCT-5)
definition: Galactic equator
pref label: Galactic equator
related: GalacticLatitude
related: GalacticLongitude
related: GalacticPole
related: MilkyWayGalaxy

GalacticHalo
type: Concept
broader: halo
change note: FVH: added RT POPULATION_III_STARS (2007-SEP-21)
change note: FVH: capitalized, since only refers to MW (2007-OCT-5)
definition: Galactic halo
pref label: Galactic halo
related: GalacticStructure
related: MilkyWayGalaxy
related: RrLyraeStar
related: globularStarCluster
related: haloStar
related: populationIiStar
related: populationIiiStar

GalacticLatitude
type: Concept
broader: latitude
change note: FVH: capitalized, since only refers to MW; moved latitude to BT (2007-OCT-5)
definition: Galactic latitude
pref label: Galactic latitude
related: GalacticCoordinateSystem
related: GalacticEquator
related: GalacticLongitude
related: GalacticPlane
related: GalacticPole
related: MilkyWayGalaxy

GalacticLongitude
type: Concept
broader: longitude
change note: FVH: capitalized, since only refers to MW; moved longitude to BT (2007-OCT-5)
definition: Galactic longitude
pref label: Galactic longitude
related: GalacticCoordinateSystem
related: GalacticEquator
related: GalacticLatitude
related: GalacticPole
related: MilkyWayGalaxy

galacticNucleus
type: Concept
broader: nucleusCelestialObject
definition: galactic nucleus
narrower: GalacticCenter
narrower: activeGalacticNucleus
narrower: compactNucleus
pref label: galactic nucleus
related: GalacticStructure
related: NGalaxy
related: blackHole
related: galaxyStructure
related: massiveObject
related: populationIiStar

GalacticPlane
type: Concept
change note: FVH: capitalized, since only refers to MW (2007-OCT-5)
definition: Galactic plane (Milky Way)
pref label: Galactic plane
related: GalacticBulge
related: GalacticLatitude
related: GalacticPole
related: GalacticWindow
related: MilkyWayGalaxy
related: diskPopulation
related: diskStar

GalacticPole
type: Concept
broader: pole
change note: FVH: capitalized, since only refers to MW (2007-OCT-5)
definition: Galactic pole (Milky Way)
narrower: NorthGalacticPole
narrower: SouthGalacticPole
pref label: Galactic pole
related: GalacticCoordinateSystem
related: GalacticEquator
related: GalacticLatitude
related: GalacticLongitude
related: GalacticPlane
related: GalacticSpurs
related: MilkyWayGalaxy

GalacticRotation
type: Concept
broader: galaxyRotationCurve
broader: rotation
change note: FVH: capitalized, since only refers to MW (2007-OCT-5)
change note: see galaxy_rotation_curve for external galaxy
definition: Galactic rotation (Milky Way)
pref label: Galactic rotation
related: DarkMatter
related: MilkyWayGalaxy
related: OortConstant
related: OortFormulae
related: cosmicYear
related: differentialRotation
related: highVelocityCloud
related: highVelocityStar
related: kinematics
related: properMotion
related: spaceMotion
related: stellarDynamics

GalacticSpurs
type: Concept
change note: FVH: capitalized, since only refers to MW (2007-OCT-5)
definition: Galactic spurs (Milky Way)
pref label: Galactic spurs
related: GalacticPole
related: GalacticStructure

GalacticStructure
type: Concept
broader: galaxyStructure
change note: FVH: capitalized, since only refers to MW; added BT galaxy_structure (2007-OCT-5)
definition: Galactic structure (Milky Way)
pref label: Galactic structure
related: GalacticBulge
related: GalacticCenter
related: GalacticHalo
related: GalacticSpurs
related: OortConstant
related: OortFormulae
related: galacticNucleus
related: kinematics
related: pitchAngle
related: spiralArm
related: starCount
scope note: See galaxy_structure for generic term (2007-OCT-5; FVH)

GalacticWindow
type: Concept
broader: window
change note: FVH: capitalized, since only refers to MW (2007-OCT-5)
change note: direction of low absorption
definition: Galactic window (Milky Way)
pref label: Galactic window
related: GalacticPlane
related: interstellarAbsorption

galaxyCluster
type: Concept
alt label: cluster of galaxies
alt label: galaxy clustering
broader: cluster
definition: cluster of galaxies
narrower: AbellCluster
narrower: LocalSupercluster
pref label: galaxy cluster
related: GreatAttractor
related: SunyaevZeldovichEffect
related: cDGalaxy
related: clustering
related: galaxyCount
related: galaxyDistribution
related: galaxyMerger
related: intergalacticMatter
related: intraclusterMatter
related: luminosityFunction
related: luminousArc
related: massDistribution
related: massiveGalaxy
related: missingMass
related: multipleGalaxy
related: protocluster
related: relaxationTime
related: supercluster
related: supergalacticCoordinateSystem
related: velocityDispersion
related: velocityDistribution
related: virialTheorem

galaxyContent
type: Concept
definition: galaxy content
pref label: galaxy content
scope note: combine with other terms

galaxyCount
type: Concept
definition: galaxy count
pref label: galaxy count
related: DarkEnergy
related: cosmology
related: galaxyCluster
related: galaxyDistribution
related: observationalCosmology

galaxyDistribution
type: Concept
definition: galaxy distribution
pref label: galaxy distribution
related: DarkEnergy
related: cosmology
related: galaxyCluster
related: galaxyCount
related: observationalCosmology

galaxyEncounter
type: Concept
broader: encounter
definition: galaxy encounter
pref label: galaxy encounter
related: galaxyMerger
related: interactingGalaxy
related: radioSource

galaxyEvolution
type: Concept
definition: galaxy evolution
pref label: galaxy evolution
related: cosmology

galaxyFormation
type: Concept
alt label: formation of galaxies
definition: galaxy formation
pref label: galaxy formation

galaxy
type: Concept
broader: extragalacticObject
broader: rotatingBody
definition: galaxy
narrower: BlLacertaeObject
narrower: DGalaxy
narrower: HaroGalaxy
narrower: LGalaxy
narrower: MagellanicCloud
narrower: MilkyWayGalaxy
narrower: NGalaxy
narrower: activeGalaxy
narrower: barredSpiralGalaxy
narrower: bipolarGalaxy
narrower: blueGalaxy
narrower: brightGalaxy
narrower: companionGalaxy
narrower: diskGalaxy
narrower: doubleGalaxy
narrower: dwarfGalaxy
narrower: earlyTypeGalaxy
narrower: ellipticalGalaxy
narrower: emissionLineGalaxy
narrower: faintGalaxy
narrower: fieldGalaxy
narrower: giantGalaxy
narrower: headTailGalaxy
narrower: hypergalaxy
narrower: infraredGalaxy
narrower: interactingGalaxy
narrower: irregularGalaxy
narrower: lateTypeGalaxy
narrower: lenticularGalaxy
narrower: massiveGalaxy
narrower: multipleGalaxy
narrower: nearbyGalaxy
narrower: peculiarGalaxy
narrower: primordialGalaxy
narrower: protogalaxy
narrower: radioGalaxy
narrower: ringGalaxy
narrower: spiralGalaxy
narrower: starburstGalaxy
pref label: galaxy
related: FanaroffRileyClass
related: HolmbergRadius
related: HubbleClassification
related: HubbleDiagram
related: LocalSupercluster
related: TullyFisherRelation
related: YerkesClassification
related: activeGalacticNucleus
related: collision
related: coma
related: coolingFlow
related: differentialRotation
related: edgeEffect
related: evolution
related: galaxyStructure
related: halo
related: integratedMagnitude
related: isophotalDiameter
related: luminosityFunction
related: massDistribution
related: massToLightRatio
related: origin
related: quasarGalaxyPair
related: surfacePhotometry
related: velocityField

galaxyGroup
type: Concept
definition: group of galaxies
narrower: HicksonCompactGroup
narrower: LocalGroup
pref label: galaxy group
related: companionGalaxy
related: multipleGalaxy

galaxyMerger
type: Concept
broader: merger
definition: galaxy merger
pref label: galaxy merger
related: doubleGalaxy
related: encounter
related: galaxyCluster
related: galaxyEncounter
related: interactingGalaxy

galaxyRotationCurve
type: Concept
broader: rotation
change note: FVH: since Galactic_rotation only refers to MW (2007-OCT-5)
definition: rotation curve of galaxy
narrower: GalacticRotation
pref label: galaxy rotation curve
related: DarkMatter
related: differentialRotation
related: galaxyStructure
related: kinematics
related: massDistribution
related: stellarDynamics

galaxyStructure
type: Concept
alt label: content of galaxy
alt label: structure of galaxy
broader: structure
change note: FVH: new, since Galactic_structure only refers to Milky Way; moved content_of_galaxy to ALT (2007-OCT-5)
change note: FVH: renamed galaxy_structure to remove _of_ (2007-OCT-24)
definition: structure of galaxy
narrower: GalacticStructure
pref label: galaxy structure
related: bulge
related: galacticNucleus
related: galaxy
related: galaxyRotationCurve
related: halo
related: interstellarMatter
related: kinematics
related: massDistribution
related: pitchAngle
related: spiralArm

galaxyVoid
type: Concept
definition: galaxy void
pref label: galaxy void
related: blankField
related: intergalacticSpace

galileanSatellite
type: Concept
broader: satellite
definition: galilean satellite
pref label: galilean satellite
related: planet

gallium
type: Concept
alt label: Ga
broader: fundamentalChemicalElement
definition: gallium (atomic number 31)
history note: FVH: new (2007-OCT-25)
pref label: gallium

gammaCassiopeiaeStar
type: Concept
broader: BDwarf
broader: emissionLineStar
broader: irregularVariableStar
broader: shellStar
definition: gamma Cassiopeiae star
pref label: gamma Cassiopeiae star

gammaRayAstronomy
type: Concept
alt label: gamma ray astronomy
broader: spaceAstronomy
definition: gamma-ray astronomy
pref label: gamma-ray astronomy
related: balloonBorneInstrument
related: rocketBorneInstrument
related: satelliteBorneInstrument

gammaRayBackground
type: Concept
alt label: gamma ray background
broader: backgroundRadiation
definition: gamma-ray background
pref label: gamma-ray background
related: XRayBackground
related: gammaRayRadiation
related: microwaveBackground
related: radioBackground
related: ultravioletBackground

gammaRayBurst
type: Concept
alt label: GRB
alt label: cosmic gamma ray burst
alt label: cosmic gamma-ray burst
alt label: gamma ray burst
broader: burst
definition: gamma-ray burst
pref label: gamma-ray burst
related: XRayBurst
related: burster
related: gammaRaySource
related: hypernova
related: opticalBurst
related: radioBurst
related: rapidBurst

gammaRayLine
type: Concept
alt label: gamma ray line
broader: gammaRayRadiation
change note: FVH: moved RT gamma-ray to BT gamma-ray_radiation (2007-OCT-8)
definition: gamma-ray line
pref label: gamma-ray line

gammaRayObservatory
type: Concept
alt label: gamma ray observatory
broader: observatory
broader: spaceObservatory
definition: gamma-ray observatory
pref label: gamma-ray observatory
related: gammaRayTelescope
scope note: see observatory for more rts

gammaRayRadiation
type: Concept
alt label: gamma radiation
alt label: gamma-ray
broader: electromagneticRadiation
broader: highEnergyRadiation
broader: nuclearRadiation
broader: radiation
definition: gamma-ray radiation
narrower: gammaRayLine
pref label: gamma-ray radiation
related: CerenkovRadiation
related: gammaRayBackground
related: gammaRayScattering
related: gammaRaySource
related: gammaRaySpectrum
related: pairAnnihilation
related: pairProduction
related: radioactivity

gammaRayScattering
type: Concept
alt label: gamma ray scattering
broader: scattering
definition: gamma-ray scattering
pref label: gamma-ray scattering
related: gammaRayRadiation

gammaRaySource
type: Concept
alt label: gamma ray source
broader: source
definition: gamma-ray source
narrower: softGammaRayRepeater
pref label: gamma-ray source
related: gammaRayBurst
related: gammaRayRadiation
related: opticalIdentification

gammaRaySpectrograph
type: Concept
alt label: gamma ray spectrograph
broader: spectrograph
definition: gamma-ray spectrograph
pref label: gamma-ray spectrograph

gammaRaySpectroscopy
type: Concept
broader: spectroscopy
definition: gamma-ray spectroscopy
pref label: gamma-ray spectroscopy
related: gammaRaySpectrum

gammaRaySpectrum
type: Concept
alt label: gamma ray spectrum
definition: gamma-ray spectrum
pref label: gamma-ray spectrum
related: gammaRayRadiation
related: gammaRaySpectroscopy

gammaRayTelescope
type: Concept
broader: spaceTelescope
broader: telescope
definition: gamma-ray telescope
pref label: gamma-ray telescope
related: gammaRayObservatory

gasCloud
type: Concept
broader: cloud
definition: gas cloud
pref label: gas cloud

gasContent
type: Concept
definition: gas content
pref label: gas content
related: gas

gasDensity
type: Concept
broader: density
definition: gas density
pref label: gas density
related: gas
related: opticalDepth

gasDistribution
type: Concept
definition: gas distribution
pref label: gas distribution
related: gas
related: spiralArm

gasDynamics
type: Concept
alt label: gas kinematics
broader: fluidDynamics
definition: gas dynamics
pref label: gas dynamics
related: gas

gaseousDisk
type: Concept
broader: disk
definition: gaseous discs UK
definition: gaseous disk
pref label: gaseous disk
related: diskStar
related: gas

gaseousNebula
type: Concept
broader: nebula
definition: gaseous nebula
narrower: emissionNebula
pref label: gaseous nebula
related: gas

gaseousSphere
type: Concept
definition: gaseous sphere
narrower: StromgrenSphere
narrower: protogalaxy
narrower: protostar
pref label: gaseous sphere
related: gas

gas
type: Concept
definition: gas
narrower: air
narrower: carbonDioxide
narrower: carbonMonoxide
narrower: ionizedGas
narrower: neutralGas
narrower: relativisticPlasma
pref label: gas
related: gasContent
related: gasDensity
related: gasDistribution
related: gasDynamics
related: gasToDustRatio
related: gaseousDisk
related: gaseousNebula
related: gaseousSphere
scope note: See also table of elements
scope note: combine with other terms

gasToDustRatio
type: Concept
definition: gas to dust ratio
pref label: gas to dust ratio
related: dust
related: gas
related: interstellarReddening
related: reddeningLaw
related: selectiveAbsorption

GBand
type: Concept
broader: FraunhoferLine
broader: molecularBand
definition: G-band
pref label: G band
related: molecularSpectrum

GDwarf
type: Concept
broader: GStar
broader: dwarf
definition: G dwarf star
pref label: G dwarf

gegenschein
type: Concept
alt label: counterglow
definition: gegenschein
pref label: gegenschein
related: interplanetaryMatter
related: nightSkyBrightness
related: zodiacalDust
related: zodiacalLight

generalTheoryOfRelativity
type: Concept
broader: gravitation
broader: relativity
definition: general theory of relativity
narrower: specialTheoryOfRelativity
pref label: general theory of relativity
related: DarkEnergy
related: NewtonianGravitation
related: SchwarzschildMetric
related: SchwarzschildRadius
related: cosmology
related: gravitationalEffect
related: gravitationalWave
related: space
related: spaceTimeCurvature
related: time

GenevaPhotometry
type: Concept
alt label: ubvgri photometry
broader: mediumBandPhotometry
broader: photometricSystem
definition: Geneva photometry
pref label: Geneva photometry
related: VilniusPhotometry

geocentricOrbit
type: Concept
broader: orbit
definition: geocentric orbit
pref label: geocentric orbit

geocorona
type: Concept
definition: geocorona
pref label: geocorona
related: Earth

geodesy
type: Concept
broader: EarthSciences
definition: geodesy
narrower: astronomicalGeodesy
narrower: spaceGeodesy
pref label: geodesy
related: Earth
related: atomicClock
related: geoid
related: pendulum

geoid
type: Concept
definition: geoid
pref label: geoid
related: Earth
related: equatorialBulge
related: geodesy

geology
type: Concept
broader: EarthSciences
definition: geology
narrower: petrology
pref label: geology
related: geophysicalObservatory
related: glaciology
related: planet
related: planetology
related: surfaceOfCelestialBody

geomagneticField
type: Concept
broader: magneticField
definition: geomagnetic field
pref label: geomagnetic field

geomagnetism
type: Concept
definition: geomagnetism
pref label: geomagnetism
related: Earth
related: continentalDrift
related: geophysicalObservatory
related: paleomagnetism
related: planet

geophysicalObservatory
type: Concept
broader: observatory
definition: geophysical observatory
pref label: geophysical observatory
related: EarthSciences
related: geology
related: geomagnetism
scope note: see observatory for more rts

geophysics
type: Concept
alt label: terrestrial physics
broader: EarthSciences
definition: geophysics
pref label: geophysics
related: Earth
related: continentalDrift

geostationarySatellite
type: Concept
broader: artificialSatellite
definition: geostationary satellite
pref label: geostationary satellite

germanium
type: Concept
alt label: Ge
broader: fundamentalChemicalElement
definition: germanium (atomic number 32)
history note: FVH: new (2007-OCT-25)
pref label: germanium

GermanMounting
type: Concept
broader: equatorialMounting
definition: German mounting
pref label: German mounting

gfValue
type: Concept
definition: gf value
pref label: gf value
related: gValue
related: lineFormation
related: lineWidth
related: logGValue
related: oscillatorStrength
related: transitionProbability

GGiant
type: Concept
broader: GStar
broader: giant
definition: G giant star
pref label: G giant
related: GSubgiant

giantBranch
type: Concept
alt label: RGB
alt label: red giant branch
definition: giant branch
narrower: blueLoop
narrower: redGiantBump
narrower: redGiantClump
narrower: redGiantTip
pref label: giant branch
related: HertzsprungGap
related: HertzsprungRussellDiagram
related: instabilityStrip
related: turnoffPoint
related: zeroAgeHorizontalBranch

giantBranchStar
type: Concept
broader: star
definition: giant branch star
pref label: giant branch star
related: horizontalBranchStar

giantEllipticalGalaxy
type: Concept
broader: ellipticalGalaxy
definition: giant elliptical galaxy
pref label: giant elliptical galaxy

giantGalaxy
type: Concept
broader: galaxy
definition: giant galaxy
narrower: cDGalaxy
pref label: giant galaxy

giant
type: Concept
alt label: CS star
broader: postMainSequenceStar
definition: giant star
narrower: AGiant
narrower: BGiant
narrower: ChStar
narrower: CnStar
narrower: FGiant
narrower: GGiant
narrower: LbVariableStar
narrower: MGiant
narrower: OhIrStar
narrower: RStar
narrower: SStar
narrower: extremeCarbonStar
narrower: lateTypeGiant
narrower: peculiarGiant
narrower: weakGBandStar
pref label: giant
related: carbonBurning
related: dredgeUp
related: lithiumStar
related: luminosityClassification
related: stellarEvolution
related: zirconiumStar

giantMolecularCloud
type: Concept
broader: molecularCloud
definition: giant molecular cloud
pref label: giant molecular cloud
related: interstellarMolecule

giantPlanet
type: Concept
broader: planet
definition: giant planet
pref label: giant planet

giantRadioGalaxy
type: Concept
broader: radioGalaxy
definition: giant radio galaxy
pref label: giant radio galaxy
related: NGalaxy
related: cDGalaxy

glaciology
type: Concept
broader: EarthSciences
definition: glaciology
pref label: glaciology
related: Earth
related: geology

glass
type: Concept
broader: opticalMaterial
definition: glass
narrower: opticalGlass
pref label: glass
related: lens
related: mirror
related: opticalFiber

glitch
type: Concept
broader: frequencyShift
definition: sudden frequency shift
history note: FVH: new (2007-OCT-8)
pref label: glitch
related: pulsar

globalPositioningSystem
type: Concept
alt label: GPS
definition: Global Positioning System
pref label: global positioning system
related: satellite
related: timeSignal
related: timeStandard
related: timeSynchronization

globularStarCluster
type: Concept
broader: starCluster
definition: globular star cluster
pref label: globular star cluster
related: GalacticHalo
related: OosterhoffGroup
related: RrLyraeStar
related: differentialRotation
related: haloStar
related: horizontalBranchStar
related: populationIiStar
related: populationIiiStar
related: turnoffPoint

globule
type: Concept
broader: interstellarMatter
definition: globule
narrower: BokGlobule
narrower: cometaryGlobule
pref label: globule
related: darkNebula

GoedelUniverse
type: Concept
broader: cosmology
definition: Goedel universe
pref label: Goedel universe

gold
type: Concept
alt label: Au
broader: fundamentalChemicalElement
definition: gold (atomic number 79)
history note: FVH: new (2007-OCT-25)
pref label: gold

GouldsBelt
type: Concept
definition: Goulds belt
pref label: Goulds belt
related: MilkyWayGalaxy
related: starAssociation

gradingFunction
type: Concept
alt label: illumination function
definition: grading function
pref label: grading function
related: apertureSynthesis

grain
type: Concept
broader: interstellarMatter
definition: grain
narrower: interplanetaryGrain
pref label: grain
related: interplanetaryDust
related: interstellarDust

granulation
type: Concept
definition: granulation
narrower: supergranulation
pref label: granulation
related: Sun
related: convection
related: facula
related: photosphere

granule
type: Concept
definition: granule
pref label: granule
related: Sun
related: photosphere

graph
type: Concept
definition: graph
pref label: graph
scope note: combine with other terms

graphite
type: Concept
definition: graphite
pref label: graphite
related: interplanetaryGrain
related: interstellarDust

graticule
type: Concept
definition: graticule
pref label: graticule
related: eyepiece
related: reticle

gratingResponse
type: Concept
definition: grating response
pref label: grating response
related: array

gratingRing
type: Concept
definition: grating ring
pref label: grating ring
related: apertureSynthesis

gratingSpectrograph
type: Concept
broader: spectrograph
definition: grating spectrograph
pref label: grating spectrograph
related: diffractionGrating
related: prismSpectrograph

gravimetry
type: Concept
definition: gravimetry
pref label: gravimetry
related: acceleration

gravitatingDisk
type: Concept
broader: disk
definition: gravitating discs UK
definition: gravitating disk
pref label: gravitating disk
related: circumstellarMatter

gravitationalCollapse
type: Concept
broader: collapse
definition: gravitational collapse
pref label: gravitational collapse
related: ChandrasekharMass
related: ChandrasekharSchoenbergLimit
related: blackHole
related: gravitation
related: gravitationalEnergy
related: supernova

gravitationalConstant
type: Concept
broader: physicalConstant
definition: Newton's gravitational constant G
pref label: gravitational constant
related: NewtonianGravitation

gravitationalDeflection
type: Concept
definition: gravitational deflection
pref label: gravitational deflection
related: EinsteinRing
related: doubleQuasar
related: gravitationalLensing

gravitationalEffect
type: Concept
definition: gravitational effect
pref label: gravitational effect
related: ModifiedNewtonianDynamics
related: generalTheoryOfRelativity

gravitationalEnergy
type: Concept
broader: energy
definition: gravitational energy
pref label: gravitational energy
related: gravitationalCollapse

gravitationalEquilibrium
type: Concept
definition: gravitational equilibrium
pref label: gravitational equilibrium
related: stellarEvolution

gravitationalField
type: Concept
alt label: gravity field
definition: gravitational field
pref label: gravitational field
related: LagrangianPoint
related: SchwarzschildMetric
related: quantumFieldTheory

gravitationalForce
type: Concept
alt label: force of gravity
broader: force
definition: gravitational force
pref label: gravitational force
related: EddingtonLimit
related: ModifiedNewtonianDynamics
related: NewtonianGravitation
related: gravitation
related: surfaceGravity

gravitationalInstability
type: Concept
definition: gravitational instability
pref label: gravitational instability
related: gravitation

gravitationalInteraction
type: Concept
broader: interaction
definition: gravitational interaction
pref label: gravitational interaction
related: encounter
related: gravitation

gravitationalLens
type: Concept
change note: FVH: effectively new, since old IAU term moved to gravitational_lensing (2007-OCT-08)
definition: gravitational lens
pref label: gravitational lens
scope note: refers to the lens themselves, not the lensing process (see gravitational_lensing)

gravitationalLensing
type: Concept
change note: FVH: removed RT white_hole, added NT gravitational_microlensing etc. (2007-OCT-8)
definition: gravitational lensing
narrower: gravitationalLensingShear
narrower: gravitationalMicrolensing
narrower: strongGravitationalLensing
narrower: weakGravitationalLensing
pref label: gravitational lensing
related: EinsteinRing
related: blackHole
related: caustic
related: causticCrossing
related: cusp
related: cuspCrossing
related: doubleQuasar
related: electromagneticRadiation
related: gravitation
related: gravitationalDeflection
related: gravitationallyLensedSource
related: luminousArc
related: massDistribution
related: visibleRadiation
related: whiteHole

gravitationalLensingShear
type: Concept
broader: gravitationalLensing
definition: gravitational lensing shear
history note: FVH: new (2007-OCT-8)
pref label: gravitational lensing shear

gravitationallyLensedSource
type: Concept
broader: source
definition: gravitationally lensed source
history note: FVH: new (2007-OCT-8)
narrower: EinsteinRing
narrower: doubleQuasar
narrower: luminousArc
pref label: gravitationally lensed source
related: gravitationalLensing

gravitationalMicrolensing
type: Concept
alt label: microlensing
broader: gravitationalLensing
change note: FVH: added gravitational_ as prefix; moved RT to BT gravitational_lensing (2007-OCT-8)
definition: microlensing
narrower: planetaryMicrolensing
narrower: quasarMicrolensing
pref label: gravitational microlensing

gravitationalRadiation
type: Concept
broader: radiation
definition: gravitational radiation
pref label: gravitational radiation
related: gravitation
related: radiationMechanism

gravitationalRedshift
type: Concept
broader: redshift
definition: gravitational redshift
pref label: gravitational redshift
related: EinsteinEffect
related: gravitation

gravitationalWave
type: Concept
broader: wave
definition: gravitational wave
pref label: gravitational wave
related: celestialMechanics
related: generalTheoryOfRelativity

gravitation
type: Concept
definition: gravitation
narrower: ModifiedNewtonianDynamics
narrower: NewtonianGravitation
narrower: generalTheoryOfRelativity
pref label: gravitation
related: LagrangianPoint
related: RocheLimit
related: celestialMechanics
related: gravitationalCollapse
related: gravitationalForce
related: gravitationalInstability
related: gravitationalInteraction
related: gravitationalLensing
related: gravitationalRadiation
related: gravitationalRedshift
related: gravity
related: mass
related: perturbationTheory
related: relativity
related: virialTheorem

graviton
type: Concept
broader: elementaryParticle
definition: graviton
pref label: graviton

gravityAnomaly
type: Concept
broader: anomaly
definition: gravity anomaly
pref label: gravity anomaly
related: magneticAnomaly
related: mascon

gravityDarkening
type: Concept
definition: gravity darkening
pref label: gravity darkening
related: surfaceBrightness
related: surfaceGravity
related: vonZeipelTheorem

gravity
type: Concept
alt label: acceleration of gravity
definition: gravity
pref label: gravity
related: JeansLength
related: gravitation
related: pendulum
related: relativisticAstrophysics
related: vonZeipelTheorem

gravityWave
type: Concept
broader: wave
definition: gravity wave
pref label: gravity wave
related: acousticWave
related: stellarInterior

grazingIncidence
type: Concept
definition: grazing incidence
pref label: grazing incidence
scope note: combine with other terms

grazingIncidenceSpectrograph
type: Concept
broader: spectrograph
definition: grazing incidence spectrograph
narrower: XRaySpectrograph
pref label: grazing incidence spectrograph

grazingIncidenceTelescope
type: Concept
broader: telescope
definition: grazing incidence telescope
narrower: XRayTelescope
pref label: grazing incidence telescope

GreatAttractor
type: Concept
definition: Great Attractor
pref label: Great Attractor
related: LocalSupercluster
related: galaxyCluster

greenhouseEffect
type: Concept
definition: greenhouse effect
pref label: greenhouse effect
related: atmosphere
related: infraredRadiation
related: planet
related: pollution
related: terrestrialRadiation

GregorianCalendar
type: Concept
broader: calendar
definition: Gregorian calendar
pref label: Gregorian calendar
related: JulianCalendar
related: time

GregorianTelescope
type: Concept
broader: telescope
definition: Gregorian telescope
pref label: Gregorian telescope

grid
type: Concept
definition: grid
pref label: grid
related: reseaux
related: reticle

grism
type: Concept
broader: opticalComponent
definition: grism
pref label: grism
related: diffractionGrating
related: prism
related: spectrograph
related: transmissionGrating

groundBasedAstronomy
type: Concept
alt label: ground based astronomy
broader: astronomy
definition: ground-based astronomy
pref label: ground-based astronomy
related: airplaneBorneInstrument
related: balloonBorneInstrument
related: rocketBorneInstrument
related: satelliteBorneInstrument
related: spaceProbeInstrument
related: spaceTelescope

GStar
type: Concept
broader: intermediateTypeStar
definition: G star
narrower: GDwarf
narrower: GGiant
narrower: GSubdwarf
narrower: GSubgiant
narrower: GSupergiant
pref label: G star
related: spectralType

GSubdwarf
type: Concept
broader: GStar
broader: subdwarf
definition: G subdwarf star
pref label: G subdwarf

GSubgiant
type: Concept
broader: GStar
broader: subgiant
definition: G subgiant star
pref label: G subgiant
related: GGiant

GSupergiant
type: Concept
broader: GStar
broader: supergiant
definition: G supergiant star
pref label: G supergiant

guideSystem
type: Concept
broader: instrument
definition: guide system
narrower: autoguider
pref label: guide system
related: controlSystem
related: quadrantDetector
related: telescope

GunnDiode
type: Concept
definition: Gunn diode
pref label: Gunn diode
related: semiconductorDevice

GunnPhotometry
type: Concept
alt label: Gunn g,r,i,z photometry
broader: broadBandPhotometry
broader: photometricSystem
definition: Gunn photometry
history note: FVH: new (2007-SEP-21)
pref label: Gunn photometry

gValue
type: Concept
definition: g value
narrower: logGValue
pref label: g value
related: gfValue
related: lineFormation
related: lineWidth
related: oscillatorStrength
related: transitionProbability

gyrosynchrotronRadiation
type: Concept
broader: synchrotronRadiation
definition: gyrosynchrotron radiation
pref label: gyrosynchrotron radiation

hadronBarrier
type: Concept
definition: hadron barrier
pref label: hadron barrier
related: BigBangTheory

hadron
type: Concept
broader: elementaryParticle
definition: hadron
pref label: hadron
related: boson

hafnium
type: Concept
alt label: Hf
broader: fundamentalChemicalElement
definition: hafnium (atomic number 72)
history note: FVH: new (2007-OCT-25)
pref label: hafnium

halation
type: Concept
definition: halation
pref label: halation
related: image
related: photographicEmulsion
related: turbidity

halfWaveDipole
type: Concept
alt label: half wave dipole
alt label: halfwave dipole
broader: dipole
definition: half-wave dipole
pref label: half-wave dipole
related: YagiAntenna
related: radioTelescope

halfWavePlate
type: Concept
alt label: half wave plate
alt label: halfwave plate
definition: half-wave plate
history note: FVH: new (2007-SEP-21)
pref label: half-wave plate
related: planePolarization
related: quarterWavePlate

halo
type: Concept
definition: halo
narrower: GalacticHalo
pref label: halo
related: comet
related: corona
related: galaxy
related: galaxyStructure
related: haloStar
related: lightScattering

haloStar
type: Concept
broader: populationIiStar
broader: populationIiiStar
broader: star
definition: halo star
pref label: halo star
related: GalacticHalo
related: globularStarCluster
related: halo
related: stellarPopulation

HAlpha
type: Concept
broader: BalmerSeries
broader: resonanceLine
definition: H alpha (656 nm)
pref label: H alpha
related: HAlphaEmissionLineStar
related: HAlphaPhotometry

HAlphaEmissionLineStar
type: Concept
definition: h alpha emission line star
pref label: H alpha emission line star
related: HAlpha
related: RwAurigaeStar
related: TAssociation
related: variableStar

HAlphaPhotometry
type: Concept
broader: narrowBandPhotometry
definition: h alpha photometry
pref label: H alpha photometry
related: HAlpha

HAndKLine
type: Concept
broader: calciumLine
definition: H and K line
narrower: HLine
narrower: KLine
pref label: H and K line

HanleEffect
type: Concept
definition: Hanle effect
pref label: Hanle effect
related: Sun
related: prominence

HarmanSeatonSequence
type: Concept
alt label: Harman Seaton sequence
definition: Harman-Seaton sequence
pref label: Harman-Seaton sequence
related: HertzsprungRussellDiagram
related: planetaryNebula
related: subdwarf

harmonicFrequency
type: Concept
alt label: harmonic overtones
alt label: harmonics
definition: harmonic frequency
pref label: harmonic frequency
related: FourierAnalysis
related: FourierComponent
related: fundamentalFrequency
related: overtoneFrequency
scope note: refers only to Fourier component of non-sinusoidal wave; see also overtone frequency

HaroGalaxy
type: Concept
broader: galaxy
definition: Haro galaxy
pref label: Haro galaxy
related: emissionLineGalaxy

HartmannTest
type: Concept
definition: Hartmann test
pref label: Hartmann test
related: figuring
related: image
related: opticalInstrument

hassium
type: Concept
alt label: Hs
broader: fundamentalChemicalElement
definition: hassium (atomic number 108)
history note: FVH: new (2007-OCT-25)
pref label: hassium

HawkingRadiation
type: Concept
definition: Hawking radiation
pref label: Hawking radiation
related: blackHole
related: eventHorizon

HayashiTrack
type: Concept
broader: evolutionaryTrack
definition: Hayashi track
pref label: Hayashi track
related: HertzsprungRussellDiagram
related: convection

HBeta
type: Concept
broader: BalmerSeries
definition: H beta (486 nm)
pref label: H beta
related: HBetaPhotometry

HBetaPhotometry
type: Concept
broader: narrowBandPhotometry
definition: h beta photometry
pref label: H beta photometry
related: HBeta
related: StromgrenPhotometry

HdCurve
type: Concept
definition: HD curve
pref label: HD curve
related: photography
scope note: Hurter and Driffield curve

HDelta
type: Concept
broader: BalmerSeries
definition: H delta (410 nm)
pref label: H delta

headTailGalaxy
type: Concept
broader: galaxy
broader: radioGalaxy
broader: radioSource
definition: head tail galaxy
pref label: head tail galaxy
related: radioStructure
related: tail

heatTransfer
type: Concept
broader: energyTransfer
definition: heat transfer
pref label: heat-transfer

heavyElement
type: Concept
broader: chemicalElement
definition: heavy element
pref label: heavy element
related: abundance

heavyMetalStar
type: Concept
broader: lateTypeGiant
broader: peculiarStar
definition: heavy metal star
pref label: heavy metal star
related: SStar
related: bariumStar
related: zirconiumStar

HeI
type: Concept
broader: helium
broader: neutralGas
definition: neutral helium
pref label: He I

height
type: Concept
alt label: elevation
definition: altitude [height]
pref label: height
scope note: use altitude [angle] for angle

HeIi
type: Concept
broader: helium
definition: once-ionized helium
pref label: He II

HeIii
type: Concept
broader: helium
definition: twice-ionized helium
pref label: He III

HeIiIonizationZone
type: Concept
alt label: He+ ionisation zone UK
alt label: He+ ionization zone
change note: FVH: replaced + with II for better parsing of token (2007-OCT-12)
definition: He II ionization zone
pref label: He II ionization zone
related: Cepheid
related: ZzCetiStar
related: deltaScutiStar
related: kappaMechanism
related: pulsatingVariableStar
related: pulsationTheory
related: radialPulsation
related: variableStar

heliocentricCorrection
type: Concept
definition: heliocentric correction
pref label: heliocentric correction
related: AstronomicalUnit
related: coordinateSystem
related: heliocentricJulianDate
related: heliocentricVelocity
scope note: correction of velocity and times to the Sun's position

heliocentricJulianDate
type: Concept
alt label: H.J.D.
alt label: HJD
broader: JulianDate
definition: heliocentric Julian Date
pref label: heliocentric Julian Date
related: heliocentricCorrection

heliocentricOrbit
type: Concept
broader: orbit
definition: heliocentric orbit
pref label: heliocentric orbit

heliocentricVelocity
type: Concept
broader: velocity
definition: heliocentric velocity
pref label: heliocentric velocity
related: heliocentricCorrection

heliograph
type: Concept
definition: heliograph
pref label: heliograph

heliometer
type: Concept
broader: measuringInstrument
definition: heliometer
pref label: heliometer

heliopause
type: Concept
definition: heliopause
pref label: heliopause
related: solarAtmosphere
related: solarWind

helioseismology
type: Concept
alt label: solar seismology
broader: asteroseismology
broader: seismology
definition: helioseismology
pref label: helioseismology
related: solarOscillation

heliosphere
type: Concept
definition: heliosphere
pref label: heliosphere
related: interplanetaryMatter
related: interstellarGas
related: solarActivity
related: solarAtmosphere
related: solarWind

heliostat
type: Concept
broader: coelostat
definition: heliostat
pref label: heliostat
related: siderostat
related: solarTelescope
related: telescopeMounting

heliumBurning
type: Concept
broader: nuclearFusion
broader: nucleosynthesis
definition: helium burning
pref label: helium burning
related: carbonBurning
related: heliumFlash
related: heliumShellFlash
related: hydrogenBurning
related: innerCore
related: oxygenBurning
related: shellBurning
related: siliconBurning
related: stellarEvolution
related: stellarInterior

heliumFlash
type: Concept
alt label: helium detonation
definition: helium flash
pref label: helium flash
related: carbonFlash
related: heliumBurning
related: heliumShellFlash
related: nuclearFusion
related: redGiantTip

helium
type: Concept
alt label: He
broader: fundamentalChemicalElement
definition: helium (atomic number 2)
history note: FVH: new (2007-OCT-25)
narrower: HeI
narrower: HeIi
narrower: HeIii
pref label: helium

heliumPoorStar
type: Concept
alt label: helium poor star
broader: star
definition: helium-poor star
narrower: BwStar
pref label: helium-poor star
related: abundance
related: metalAbundance

heliumRichStar
type: Concept
alt label: helium rich star
broader: star
change note: FVH: added NT DB_STARS (2007-OCT-1)
definition: helium-rich star
narrower: DbStar
pref label: helium-rich star
related: abundance
related: metalAbundance

heliumShellFlash
type: Concept
definition: helium shell flash
pref label: helium shell flash
related: heliumBurning
related: heliumFlash
related: nuclearFusion

HelmholtzKelvinContraction
type: Concept
alt label: Helmholtz Kelvin contraction
alt label: Kelvin-Helmholtz contraction
definition: Helmholtz-Kelvin contraction
pref label: Helmholtz-Kelvin contraction
related: KelvinTimescale

HenryDraperCatalog
type: Concept
broader: catalog
definition: henry draper catalog
pref label: Henry Draper catalog
related: HenryDraperSystem
related: spectralClassification

HenryDraperSystem
type: Concept
alt label: HD system
alt label: Harvard classification
broader: spectralClassification
definition: Henry-Draper system
pref label: Henry Draper system
related: HenryDraperCatalog

HenyeyTrack
type: Concept
broader: evolutionaryTrack
definition: Henyey track
pref label: Henyey track
related: HertzsprungRussellDiagram
related: stellarEvolution

HEpsilon
type: Concept
broader: BalmerSeries
definition: H epsilon
pref label: H epsilon

HerbigAeBeStar
type: Concept
alt label: Herbig Ae-Be star
alt label: Herbig star
broader: AeStar
broader: BeStar
definition: Herbig AeBe star
narrower: AeStar
narrower: BeStar
pref label: Herbig AeBe star

HerbigHaroObject
type: Concept
alt label: HH-object
broader: emissionLineObject
broader: emissionNebula
broader: infraredSource
broader: intrinsicVariableStar
broader: preMainSequenceStar
definition: Herbig-Haro object
pref label: Herbig-Haro object
related: TAssociation
related: TTauriStar
related: protostar

HertzsprungGap
type: Concept
definition: Hertzsprung gap
pref label: Hertzsprung gap
related: HertzsprungRussellDiagram
related: giantBranch

HertzsprungRussellDiagram
type: Concept
alt label: HR diagram
alt label: Hertzsprung Russell diagram
definition: Hertzsprung-Russell diagram
pref label: Hertzsprung-Russell diagram
related: HarmanSeatonSequence
related: HayashiTrack
related: HenyeyTrack
related: HertzsprungGap
related: HessDiagram
related: absoluteMagnitude
related: asymptoticGiantBranch
related: colorLuminosityRelation
related: colorMagnitudeRelation
related: evolutionaryTrack
related: giantBranch
related: instabilityStrip
related: luminosity
related: mainSequence
related: postAsymptoticGiantBranch
related: redGiantTip
related: spectrum
related: stellarEvolution
related: turnoffPoint
related: zeroAgeHorizontalBranch
related: zeroAgeMainSequence

HessDiagram
type: Concept
definition: Hess diagram
pref label: Hess diagram
related: HertzsprungRussellDiagram
related: frequencyDistribution

heterodyne
type: Concept
definition: heterodyne
pref label: heterodyne
related: interferometer
related: spectroscopy
scope note: combine with other terms

HGamma
type: Concept
broader: BalmerSeries
definition: H gamma (434 nm)
pref label: H gamma

HI
type: Concept
alt label: neutral hydrogen
broader: hydrogen
broader: neutralGas
definition: H I
pref label: H I
related: 21CmLine
related: HIAbsorption
related: HICloud
related: HIContent
related: HIEmission
related: HIRegion

HIAbsorption
type: Concept
definition: H I absorption
pref label: H I absorption
related: 21CmLine
related: HI
related: HICloud

HicksonCompactGroup
type: Concept
alt label: HCG
broader: galaxyGroup
definition: Hickson compact group of galaxies
history note: FVH: new (2007-OCT-8)
pref label: Hickson compact group

HICloud
type: Concept
definition: H I cloud
pref label: H I cloud
related: 21CmLine
related: HI
related: HIAbsorption

HIContent
type: Concept
definition: H I content
pref label: H I content
related: 21CmLine
related: HI

HIEmission
type: Concept
definition: H I emission
pref label: H I emission
related: 21CmLine
related: HI
related: emissionSpectrum

hierarchicalCosmology
type: Concept
broader: cosmology
definition: hierarchical cosmology
pref label: hierarchical cosmology

highEnergyAstrophysics
type: Concept
alt label: high energy astrophysics
alt label: high energy process
alt label: high-energy process
broader: astrophysics
definition: high-energy astrophysics
pref label: high-energy astrophysics
related: cosmicRayAstronomy
related: inverseComptonEffect
related: nuclearAstrophysics
related: particleBeam

highEnergyRadiation
type: Concept
alt label: high energy radiation
broader: radiation
definition: high-energy radiation
narrower: XRayRadiation
narrower: cosmicRay
narrower: gammaRayRadiation
pref label: high-energy radiation
related: XRayLuminosity

highLuminosityStar
type: Concept
alt label: high luminosity star
alt label: luminous star
broader: star
definition: high-luminosity star
narrower: brightStar
narrower: luminousBlueVariableStar
narrower: nova
narrower: supergiant
narrower: supernova
pref label: high-luminosity star

highMassStar
type: Concept
broader: star
definition: high-mass star
history note: FVH: new (2007-OCT-9)
narrower: highMassXRayBinaryStar
pref label: high-mass star

highMassXRayBinaryStar
type: Concept
broader: XRayBinaryStar
broader: highMassStar
definition: high-mass X-ray binary star
history note: ES: new (2007-OCT-8)
pref label: high-mass X-ray binary star
related: lowMassXRayBinaryStar

highResolutionSpectrosopy
type: Concept
alt label: high dispersion spectroscopy
alt label: high resolution spectrosopy
alt label: high-dispersion spectroscopy
broader: spectroscopy
definition: high-resolution spectrosopy
pref label: high-resolution spectrosopy
related: CoudeSpectrograph
related: echelleSpectrograph

highResolutionSpectrum
type: Concept
alt label: high dispersion spectrum
alt label: high resolution spectrum
alt label: high-dispersion spectrum
definition: high-resolution spectrum
narrower: CoudeSpectrum
narrower: echelleSpectrum
pref label: high-resolution spectrum
related: CoudeSpectrograph
related: echelleSpectrograph

highSpeedPhotometer
type: Concept
alt label: high speed photometer
broader: photometer
definition: high-speed photometer
pref label: high-speed photometer
related: timeResolvedSpectroscopy
related: variableStar

highState
type: Concept
definition: photometric high state of variable object
history note: FVH: new (2007-OCT-8)
pref label: high-state
related: lowState
related: outburst
related: variability
related: variableSource

highTemperature
type: Concept
alt label: high temperature
alt label: hot
definition: high-temperature
pref label: high-temperature
scope note: combine with other terms

highVelocityCloud
type: Concept
alt label: HVC
alt label: high velocity cloud
broader: cloud
change note: FVH: added ALT HVC (2007-SEP-21)
definition: high-velocity cloud
pref label: high-velocity cloud
related: GalacticRotation
related: MilkyWayGalaxy
related: highVelocityStar
related: velocity

highVelocityStar
type: Concept
alt label: high velocity star
broader: star
definition: high-velocity star
pref label: high-velocity star
related: GalacticRotation
related: MilkyWayGalaxy
related: highVelocityCloud
related: orbit
related: runawayStar
related: velocity

HIi
type: Concept
alt label: ionized hydrogen
broader: hydrogen
broader: ionizedGas
definition: H II
pref label: H II
related: HIiRegion

HIiRegion
type: Concept
alt label: HII region
broader: emissionLineObject
broader: emissionNebula
broader: interstellarMatter
definition: H II region
narrower: compactHIiRegion
pref label: H II region
related: BokGlobule
related: FaradayEffect
related: HIi
related: cometaryGlobule
related: emissionLine
related: emissionLineGalaxy
related: excitingStar
related: plasma
related: radioRecombinationLine
related: youngStar

HirayamaFamily
type: Concept
broader: minorPlanetFamily
definition: Hirayama family
pref label: Hirayama family
related: ApolloGroup

HIRegion
type: Concept
broader: interstellarMatter
definition: H I region
pref label: H I region
related: 21CmLine
related: HI
related: neutralGas
related: radioAbsorption
related: radioRecombinationLine

historyOfAstronomy
type: Concept
definition: history of astronomy
narrower: archaeoastronomy
pref label: history of astronomy
scope note: combine with other terms

HLine
type: Concept
broader: FraunhoferLine
broader: HAndKLine
definition: H line
pref label: H line
related: KLine

HMagnitude
type: Concept
broader: apparentMagnitude
definition: H magnitude
pref label: H magnitude
related: infraredPhotometry
related: nearInfraredRadiation

HolmbergRadius
type: Concept
definition: Holmberg radius
pref label: Holmberg radius
related: galaxy

holmium
type: Concept
alt label: Ho
broader: fundamentalChemicalElement
broader: rareEarth
definition: holmium (atomic number 67)
history note: FVH: new (2007-OCT-25)
pref label: holmium
related: holmiumStar

holmiumStar
type: Concept
broader: ApStar
broader: peculiarStar
definition: holmium star
pref label: holmium star
related: holmium

HoltsmarkApproximation
type: Concept
definition: Holtsmark approximation
pref label: Holtsmark approximation
related: plasma

horizonCoordinateSystem
type: Concept
broader: coordinateSystem
definition: horizon coordinate system
pref label: horizon coordinate system
related: altazimuthMounting
related: altitudeAngle
related: azimuth
related: horizon
related: meridian
related: nadir
related: zenith

horizon
type: Concept
definition: horizon
pref label: horizon
related: altitudeAngle
related: azimuth
related: celestialSphere
related: horizonCoordinateSystem

horizontalBranchStar
type: Concept
broader: evolvedStar
broader: populationIiStar
definition: horizontal branch star
narrower: extremeHorizontalBranchStar
pref label: horizontal branch star
related: RrLyraeStar
related: giantBranchStar
related: globularStarCluster

horizontalParallax
type: Concept
broader: diurnalParallax
definition: horizontal parallax
pref label: horizontal parallax

hornAntenna
type: Concept
alt label: horn antennas
broader: antenna
broader: radioWaveguide
definition: horn antenna
pref label: horn antenna
related: feedHorn

horseshoeMounting
type: Concept
broader: equatorialMounting
definition: horseshoe mounting
pref label: horseshoe mounting

hourAngle
type: Concept
alt label: HA
definition: hour angle
pref label: hour angle
related: RightAscension
related: siderealTime
related: transitTime

HstPhotometry
type: Concept
alt label: HST Fnnn[LMNW] photometry
alt label: Hubble photometry
broader: broadBandPhotometry
broader: photometricSystem
definition: HST photometry
history note: FVH: new (2007-SEP-21)
pref label: HST photometry
related: HubbleSpaceTelescope

HubbleClassification
type: Concept
alt label: Hubble sequence
definition: Hubble classification
pref label: Hubble classification
related: galaxy

HubbleConstant
type: Concept
broader: cosmologicalParameter
definition: Hubble constant
pref label: Hubble constant
related: HubbleTime
related: cosmologicalDistanceScale
related: cosmology
related: redshiftMagnitudeRelation

HubbleDiagram
type: Concept
broader: statisticalRelation
definition: Hubble diagram
pref label: Hubble diagram
related: cosmology
related: galaxy
related: redshift
related: redshiftMagnitudeRelation

HubbleLaw
type: Concept
broader: statisticalRelation
definition: Hubble law
pref label: Hubble law
related: DarkEnergy
related: cosmology
related: observationalCosmology
related: redshift
related: redshiftMagnitudeRelation

HubbleRadius
type: Concept
definition: Hubble radius
pref label: Hubble radius
related: BigBangTheory
related: cosmology

HubbleSandageVariableStar
type: Concept
alt label: H S variable star
alt label: H-S variable star
definition: Hubble-Sandage variable star
pref label: Hubble Sandage variable star
related: supergiant

HubbleSpaceTelescope
type: Concept
alt label: HST
broader: opticalObservatory
broader: spaceObservatory
broader: ultravioletObservatory
definition: Hubble Space Telescope
history note: FVH: new, because of HST_photometry (2007-NOV-1)
pref label: Hubble Space Telescope
related: HstPhotometry

HubbleTime
type: Concept
definition: Hubble time
pref label: Hubble time
related: BigBangTheory
related: HubbleConstant
related: age
related: cosmology

hydratedCarbon
type: Concept
alt label: CH
broader: carbonCompound
broader: hydrocarbon
broader: interstellarMolecule
broader: molecule
change note: FVH: moved CH to ALT to conform to standard use in the thesaurus (2007-OCT-5)
definition: CH molecule
pref label: hydrated carbon

hydrocarbon
type: Concept
definition: hydrocarbon
narrower: Cs
narrower: ethane
narrower: ethylene
narrower: hydratedCarbon
narrower: polycyclicHydrocarbon
pref label: hydrocarbon

hydrodynamics
type: Concept
broader: fluidDynamics
definition: hydrodynamics
pref label: hydrodynamics
related: jet
related: magnetohydrodynamics

hydrogenBurning
type: Concept
broader: nucleosynthesis
definition: hydrogen burning
narrower: carbonNitrogenCycle
narrower: protonProtonReaction
pref label: hydrogen burning
related: ChandrasekharMass
related: ChandrasekharSchoenbergLimit
related: carbonBurning
related: heliumBurning
related: hydrogen
related: innerCore
related: nuclearFusion
related: oxygenBurning
related: shellBurning
related: siliconBurning
related: stellarEvolution
related: stellarInterior

hydrogenDeficientStar
type: Concept
broader: star
definition: hydrogen-deficient star
narrower: AmCanumVenaticorumStar
pref label: hydrogen deficient star
related: hydrogen
related: metalAbundance

hydrogen
type: Concept
alt label: H
broader: fundamentalChemicalElement
definition: hydrogen (atomic number 1)
history note: FVH: new (2007-OCT-25)
narrower: HI
narrower: HIi
narrower: deuterium
narrower: molecularHydrogen
narrower: negativeHIon
narrower: tritium
pref label: hydrogen
related: 21CmLine
related: hydrogenBurning
related: hydrogenDeficientStar
related: hydrogenSpectrum

hydrogenLine
type: Concept
definition: hydrogen line
pref label: hydrogen line
scope note: see hydrogen spectrum

hydrogenSpectrum
type: Concept
broader: spectrum
definition: hydrogen spectrum
narrower: BalmerContinuum
narrower: BalmerSeries
narrower: BrackettSeries
narrower: LymanContinuum
narrower: LymanSeries
narrower: PaschenSeries
narrower: PfundSeries
pref label: hydrogen spectrum
related: hydrogen

hydrostaticEquilibrium
type: Concept
definition: hydrostatic equilibrium
pref label: hydrostatic equilibrium
related: stellarStructure

hydroxylRadical
type: Concept
alt label: OH
alt label: OH radical
broader: interstellarMolecule
broader: ion
broader: radical
definition: hydroxyl radical
pref label: hydroxyl radical
related: OhAbsorption
related: OhCloud
related: OhEmission
related: OhIrStar
related: OhLine
related: OhMaser
related: OhSource

hyperbolicOrbit
type: Concept
broader: orbit
definition: hyperbolic orbit
pref label: hyperbolic orbit
related: circularOrbit
related: ellipticalOrbit
related: parabolicOrbit

hyperfineLine
type: Concept
broader: spectralLine
definition: hyperfine line
pref label: hyperfine line
related: spectrum

hypergalaxy
type: Concept
broader: galaxy
definition: hypergalaxy
pref label: hypergalaxy

hypergiant
type: Concept
broader: star
definition: hypergiant star
pref label: hypergiant
related: supergiant

hypernova
type: Concept
broader: supernova
definition: hypernova
history note: FVH: new (2007-OCT-5)
pref label: hypernova
related: gammaRayBurst
related: stellarBlackHole

hypotheticalPlanet
type: Concept
broader: planet
definition: hypothetical planet
pref label: hypothetical planet

HzHerculisStar
type: Concept
broader: XRayPulsar
broader: lowMassStar
broader: neutronStar
definition: HZ Herculis star
pref label: HZ Herculis star
related: XRayBinaryStar
related: XRayBurst

identification
type: Concept
definition: identification
pref label: identification
scope note: e.g. catalog number, etc

IGalaxy
type: Concept
broader: irregularGalaxy
definition: irregular galaxy (Yerkes classification scheme)
history note: FVH: new (2007-OCT-12)
pref label: I galaxy
related: YerkesClassification

illumination
type: Concept
definition: illumination
pref label: illumination
related: albedo
related: brightness
related: intensity
related: lunarPhase
related: radiation
scope note: of solar system body

image
type: Concept
definition: image
narrower: digitalImage
narrower: photograph
pref label: image
related: HartmannTest
related: halation
related: photography
related: vision

imageProcessing
type: Concept
definition: image processing
pref label: image processing
related: cleanMethod
related: flatField
related: imageReconstruction
related: twoDimensionalDetector

imageReconstruction
type: Concept
definition: image reconstruction
pref label: image reconstruction
related: cleanMethod
related: imageProcessing

imageTube
type: Concept
alt label: image converters
alt label: image intensifier
alt label: light amplifier
alt label: photoelectric image tube
broader: multiChannelDetector
broader: photoelectricInstrument
broader: photoelectronicDevice
broader: twoDimensionalDetector
definition: image tube
pref label: image tube
related: amplifier
related: electrode
related: electronicCamera
related: microchannelPlate
related: phosphorescence
related: phosphorescentScintillation
related: photocathode
related: quantumEfficiency
related: scintillationCounter

imagingInstrument
type: Concept
broader: instrument
definition: imaging instrument
pref label: imaging instrument
scope note: combine with other terms

IMagnitude
type: Concept
broader: apparentMagnitude
definition: I magnitude
pref label: I magnitude
related: BesselPhotometry
related: JohnsonPhotometry
related: KronCousinsPhotometry
related: infraredPhotometry
related: nearInfraredRadiation

impactCrater
type: Concept
broader: crater
definition: impact crater
pref label: impact crater
related: meteorite

impersonalAstrolabe
type: Concept
broader: astrolabe
definition: impersonal astrolabe
pref label: impersonal astrolabe

inclination
type: Concept
broader: orbitalElement
definition: inclination
pref label: inclination
related: binaryStar
related: node

indium
type: Concept
alt label: In
broader: fundamentalChemicalElement
definition: indium (atomic number 49)
history note: FVH: new (2007-OCT-25)
pref label: indium

indochinite
type: Concept
broader: tektite
definition: indochinite
pref label: indochinite

inertialCoordinateSystem
type: Concept
broader: coordinateSystem
definition: inertial coordinate system
pref label: inertial coordinate system
related: inertialReferenceFrame
related: relativity

inertialReferenceFrame
type: Concept
definition: inertial reference frame
pref label: inertial reference frame
related: inertialCoordinateSystem
related: relativity

inflationaryUniverse
type: Concept
broader: cosmology
definition: inflationary universe
pref label: inflationary universe

infraredAstronomy
type: Concept
broader: astronomy
definition: infrared astronomy
pref label: infrared astronomy
related: infraredRadiation
related: infraredTelescope
related: satelliteBorneInstrument

infraredDetector
type: Concept
broader: detector
definition: infrared detector
pref label: infrared detector
related: photometer

infraredEmission
type: Concept
broader: emissionSpectrum
definition: infrared emission
pref label: infrared emission
related: thermalEmission

infraredGalaxy
type: Concept
broader: galaxy
broader: infraredSource
definition: infrared galaxy
narrower: IrasGalaxy
pref label: infrared galaxy

infrared
type: Concept
definition: infrared
pref label: infrared
related: infraredRadiation
scope note: combine with other terms

infraredObservatory
type: Concept
broader: observatory
definition: infrared observatory
narrower: IrasSatellite
pref label: infrared observatory
related: airplaneBorneInstrument
related: infraredSource
related: rocketBorneInstrument
related: spaceObservatory
scope note: see observatory for more rts

infraredPhotometry
type: Concept
broader: broadBandPhotometry
broader: mediumBandPhotometry
broader: photometry
definition: infrared photometry
pref label: infrared photometry
related: HMagnitude
related: IMagnitude
related: JMagnitude
related: KMagnitude
related: LMagnitude
related: MMagnitude
related: NMagnitude
related: OMagnitude
related: PMagnitude
related: QMagnitude
related: farInfraredRadiation
related: nearInfraredRadiation

infraredRadiation
type: Concept
broader: electromagneticRadiation
broader: radiation
definition: infrared radiation
narrower: BrackettSeries
narrower: PfundSeries
narrower: PhillipsBand
narrower: farInfraredRadiation
narrower: nearInfraredRadiation
pref label: infrared radiation
related: IrasSatellite
related: greenhouseEffect
related: infrared
related: infraredAstronomy
related: remoteSensing
related: terrestrialRadiation
related: thermalRadiation

infraredSource
type: Concept
broader: source
definition: infrared source
narrower: FuOrionisStar
narrower: HerbigHaroObject
narrower: OhIrStar
narrower: cocoonStar
narrower: extremeCarbonStar
narrower: flareStar
narrower: infraredGalaxy
pref label: infrared source
related: infraredObservatory
related: starFormation

infraredTelescope
type: Concept
broader: telescope
definition: infrared telescope
pref label: infrared telescope
related: infraredAstronomy

infraredTransmissionWindow
type: Concept
broader: atmosphericWindow
change note: FVH: renamed to avoid confusion with optics (2007-NOV-2)
definition: infrared transmission window through the atmosphere
pref label: infrared transmission window
related: opticalTransmissionWindow
related: radioTransmissionWindow
scope note: low absorption in atmosphere

inhomogenity
type: Concept
definition: inhomogenity
pref label: inhomogenity
scope note: combine with other terms

initialMassFunction
type: Concept
alt label: IMF
definition: initial mass function
pref label: initial mass function
related: mass
related: massRatio
related: starCluster
related: stellarEvolution

innerCore
type: Concept
definition: inner core
pref label: inner core
related: heliumBurning
related: hydrogenBurning
related: stellarEvolution
related: stellarInterior
scope note: central region of star

innerPlanet
type: Concept
alt label: terrestrial planet
broader: planet
definition: inner planet
pref label: inner planet
related: outerPlanet

instability
type: Concept
definition: instability
narrower: RayleighTaylorInstability
pref label: instability
scope note: combine with other terms

instabilityStrip
type: Concept
definition: instability strip
pref label: instability strip
related: Cepheid
related: HertzsprungRussellDiagram
related: giantBranch
related: stellarEvolution

instrumentalProfile
type: Concept
broader: lineProfile
definition: instrumental profile
pref label: instrumental profile
related: equivalentWidth
related: lineBroadening
related: lineWidth
related: spectralLine

instrument
type: Concept
alt label: astronomical instrument
alt label: instrumentation
definition: instrument
narrower: airplaneBorneInstrument
narrower: amplifier
narrower: armillarySphere
narrower: astrolabe
narrower: astrometricInstrument
narrower: auxiliaryInstrument
narrower: blinkComparator
narrower: bolometer
narrower: coronagraph
narrower: detector
narrower: guideSystem
narrower: imagingInstrument
narrower: interferometer
narrower: magnetograph
narrower: magnetoheliograph
narrower: quadrant
narrower: sextant
narrower: spectrograph
narrower: stroboscope
narrower: telescopeInstrument
pref label: instrument
related: calibration
related: electronicEquipment
related: frequencyStandard
related: metrology
related: peripheral
related: supportSystem
scope note: only the broad classes are shown below; specific type will be found under these, or from the hierarchical list

integralFieldSpectrograph
type: Concept
broader: spectrograph
definition: integral field spectrograph
history note: FVH: new (2007-SEP-21)
pref label: integral field spectrograph
related: multiFiberSpectrograph
related: multiSlitSpectrograph
related: threeDimensionalSpectrum

integratedMagnitude
type: Concept
alt label: total magnitude
broader: magnitude
definition: integrated magnitude
pref label: integrated magnitude
related: galaxy
related: starCluster

integrationTime
type: Concept
definition: integration time
pref label: integration time
related: brightness
related: noise
related: sensitivity
related: signalToNoiseRatio

intensity
type: Concept
alt label: specific intensity
definition: intensity
narrower: apparentIntensity
pref label: intensity
related: brightness
related: illumination
related: luminosity
related: magnitude
scope note: combine with other terms

intensityInterferometer
type: Concept
broader: interferometer
broader: opticalInterferometer
definition: intensity interferometer
pref label: intensity interferometer
related: MichelsonInterferometer

interactingBinaryStar
type: Concept
broader: binaryStar
definition: interacting binary star
narrower: XRayBinaryStar
narrower: cataclysmicVariableStar
pref label: interacting binary star
related: RocheLobe
related: XRayBrightPoint
related: eclipsingBinaryStar
related: eruptiveBinaryStar
related: tidalFriction
related: tidalInteraction

interactingGalaxy
type: Concept
broader: galaxy
broader: peculiarGalaxy
definition: interacting galaxy
pref label: interacting galaxy
related: galaxyEncounter
related: galaxyMerger
related: tail
related: tidalDistortion
related: tidalFriction
related: tidalInteraction

interaction
type: Concept
definition: interaction
narrower: electromagneticInteraction
narrower: gravitationalInteraction
narrower: strongInteraction
narrower: weakInteraction
pref label: interaction
related: equationOfState
related: nuclearPhysics

intercloudGas
type: Concept
broader: intercloudMatter
definition: intercloud gas
pref label: intercloud gas

intercloudMatter
type: Concept
broader: interstellarMatter
definition: intercloud matter
narrower: intercloudGas
pref label: intercloud matter

interferenceFilter
type: Concept
broader: filter
broader: opticalComponent
broader: opticalFilter
definition: interference filter
pref label: interference filter
related: interferenceWave
related: opticalFilm
related: photometry
related: ultravioletFilter

interferenceFringe
type: Concept
alt label: fringe
alt label: fringe patterns
definition: interference fringe
pref label: interference fringe
related: interferenceWave
related: interferometer
related: interferometry
related: opticalInterferometry
related: visibilityFunction

interferenceNoise
type: Concept
broader: noise
definition: interference [noise]
pref label: interference noise

interferenceSpectrosocopy
type: Concept
broader: spectroscopy
definition: interference spectrosocopy
pref label: interference spectrosocopy
related: interferenceWave

interferenceWave
type: Concept
definition: interference [wave]
narrower: lightInterference
pref label: interference wave
related: diffraction
related: interferenceFilter
related: interferenceFringe
related: interferenceSpectrosocopy
related: interferometry
related: opticalInterferometry
related: radioInterferometry
related: shadowBand
related: waveMotion

interferometer
type: Concept
broader: instrument
definition: interferometer
narrower: FabryPerotInterferometer
narrower: intensityInterferometer
narrower: longBaselineInterferometer
narrower: opticalInterferometer
narrower: phaseSwitchingInterferometer
narrower: radioInterferometer
narrower: veryLongBaselineInterferometer
pref label: interferometer
related: antenna
related: array
related: heterodyne
related: interferenceFringe
related: radioTelescope
related: telescopeArray
scope note: see also under interferometry

interferometricCorrelation
type: Concept
broader: correlation
change note: FVH: changed from correlation to avoid mixup with generic term (2007-OCT-26)
definition: interferometric correlation
pref label: interferometric correlation
related: crossCorrelation
related: interferometry
related: receiver
scope note: combine with other terms

interferometry
type: Concept
broader: astronomicalTechnique
broader: observingTechnique
definition: interferometry
narrower: longBaselineInterferometry
narrower: opticalInterferometry
narrower: radioInterferometry
narrower: speckleInterferometry
narrower: veryLongBaselineInterferometry
pref label: interferometry
related: angularDiameter
related: apertureSynthesis
related: correlation
related: interferenceFringe
related: interferenceWave
related: interferometricCorrelation
related: radioAstrometry
related: resolution
related: visibilityFunction
scope note: see also under interferometer

intergalacticAbsorption
type: Concept
broader: absorption
definition: intergalactic absorption
pref label: intergalactic absorption
related: LymanAlphaForest
related: absorptionCoefficient
related: intergalacticMatter
related: intergalacticSpace
related: interstellarAbsorption
related: reddening

intergalacticCloud
type: Concept
broader: intergalacticMatter
definition: intergalactic cloud
pref label: intergalactic cloud
related: intergalacticGas

intergalacticGas
type: Concept
broader: intergalacticMatter
definition: intergalactic gas
pref label: intergalactic gas
related: intergalacticCloud

intergalacticMatter
type: Concept
definition: intergalactic matter
narrower: DarkMatter
narrower: dust
narrower: intergalacticCloud
narrower: intergalacticGas
pref label: intergalactic matter
related: cosmicString
related: galaxyCluster
related: intergalacticAbsorption
related: intergalacticSpace
related: interplanetaryMatter
related: interstellarMatter
related: intraclusterMatter

intergalacticSpace
type: Concept
definition: intergalactic space
pref label: intergalactic space
related: galaxyVoid
related: intergalacticAbsorption
related: intergalacticMatter

interior
type: Concept
definition: interior
pref label: interior
related: planet
scope note: combine with other terms

intermediatePopulationStar
type: Concept
broader: star
definition: intermediate population star
pref label: intermediate population star
related: populationIiStar
related: stellarPopulation

intermediateTypeStar
type: Concept
definition: intermediate type star
narrower: FStar
narrower: GStar
pref label: intermediate type star

internalMotion
type: Concept
broader: motion
definition: internal motion
pref label: internal motion
scope note: combine with other terms

interplanetaryDust
type: Concept
broader: dust
broader: interplanetaryMatter
definition: interplanetary dust
narrower: meteoroid
pref label: interplanetary dust
related: grain
related: interplanetaryGas

interplanetaryGas
type: Concept
broader: interplanetaryMatter
definition: interplanetary gas
pref label: interplanetary gas
related: interplanetaryDust
related: interplanetaryGrain
related: solarWind

interplanetaryGrain
type: Concept
broader: grain
broader: interplanetaryMatter
definition: interplanetary grain
narrower: meteoroid
pref label: interplanetary grain
related: adsorption
related: graphite
related: interplanetaryGas

interplanetaryMagneticField
type: Concept
broader: magneticField
definition: interplanetary magnetic field
pref label: interplanetary magnetic field

interplanetaryMatter
type: Concept
alt label: interplanetary medium
definition: interplanetary matter
narrower: interplanetaryDust
narrower: interplanetaryGas
narrower: interplanetaryGrain
narrower: meteoroid
narrower: solarWind
pref label: interplanetary matter
related: asteroid
related: circumstellarMatter
related: comet
related: gegenschein
related: heliosphere
related: intergalacticMatter
related: interplanetaryScintillation
related: interstellarMatter
related: meteorite
related: micrometeorite
related: zodiacalDust
related: zodiacalLight

interplanetaryScintillation
type: Concept
broader: scintillation
definition: interplanetary scintillation
pref label: interplanetary scintillation
related: interplanetaryMatter
related: interstellarScintillation
related: ionosphericScintillation
related: radioSource

interstellarAbsorption
type: Concept
alt label: interstellar extinction
broader: absorption
definition: interstellar absorption
narrower: OhAbsorption
pref label: interstellar absorption
related: GalacticWindow
related: RayleighScattering
related: WolfDiagram
related: absorptionCoefficient
related: intergalacticAbsorption
related: interstellarDust
related: interstellarGas
related: interstellarReddening
related: lightAbsorption
related: reddenedStar
related: reddening
related: window

interstellarBubble
type: Concept
broader: bubble
definition: interstellar bubble
pref label: interstellar bubble
scope note: combine with other terms

interstellarCommunication
type: Concept
definition: interstellar communication
pref label: interstellar communication
related: extraterrestrialLife
related: spaceExploration

interstellarDust
type: Concept
broader: dust
broader: interstellarMatter
definition: interstellar dust
pref label: interstellar dust
related: adsorption
related: dustCloud
related: grain
related: graphite
related: interstellarAbsorption
related: interstellarGas
related: reddening

interstellarGas
type: Concept
broader: interstellarMatter
definition: interstellar gas
pref label: interstellar gas
related: absorption
related: heliosphere
related: interstellarAbsorption
related: interstellarDust
related: interstellarWind
related: reddening

interstellarMagneticField
type: Concept
broader: magneticField
definition: interstellar magnetic field
pref label: interstellar magnetic field
related: spiralArm

interstellarMatter
type: Concept
alt label: interstellar medium
definition: interstellar matter
narrower: BokGlobule
narrower: CIiRegion
narrower: DarkMatter
narrower: HIRegion
narrower: HIiRegion
narrower: OhCloud
narrower: cometaryGlobule
narrower: darkCloud
narrower: darkNebula
narrower: denseCloud
narrower: dust
narrower: dustCloud
narrower: dustGrain
narrower: dustNebula
narrower: globule
narrower: grain
narrower: intercloudMatter
narrower: interstellarDust
narrower: interstellarGas
narrower: interstellarMolecule
narrower: molecularCloud
narrower: nebula
narrower: nebularFilament
narrower: reflectionNebula
pref label: interstellar matter
related: SiOMaser
related: StromgrenSphere
related: circumstellarMatter
related: cosmicString
related: galaxyStructure
related: intergalacticMatter
related: interplanetaryMatter
related: interstellarReddening
related: interstellarScintillation
related: maser
related: radioAbsorption
related: radioTransmissionWindow
related: selectiveAbsorption
related: spiralArm
related: torus

interstellarMolecule
type: Concept
broader: interstellarMatter
broader: molecule
definition: interstellar molecule
narrower: Cs
narrower: ammonia
narrower: carbonCompound
narrower: hydratedCarbon
narrower: hydroxylRadical
narrower: methane
narrower: molecularHydrogen
narrower: water
pref label: interstellar molecule
related: cosmochemistry
related: giantMolecularCloud
related: molecularCloud
related: organicMolecule
scope note: not a complete list of nts

interstellarReddening
type: Concept
broader: reddening
definition: interstellar reddening
pref label: interstellar reddening
related: colorExcess
related: gasToDustRatio
related: interstellarAbsorption
related: interstellarMatter
related: lightAbsorption
related: lightScattering
related: reddenedStar
related: reddeningLaw
related: selectiveAbsorption

interstellarScintillation
type: Concept
broader: scintillation
definition: interstellar scintillation
pref label: interstellar scintillation
related: interplanetaryScintillation
related: interstellarMatter
related: ionosphericScintillation
related: radioSource

interstellarWind
type: Concept
definition: interstellar wind
pref label: interstellar wind
related: interstellarGas
related: solarWind
related: stellarWind

intraclusterMatter
type: Concept
definition: intracluster matter
pref label: intracluster matter
related: SunyaevZeldovichEffect
related: galaxyCluster
related: intergalacticMatter

intrinsicColor
type: Concept
definition: intrinsic color
pref label: intrinsic color
related: colorIndex
related: photometry
related: reddening

intrinsicVariableStar
type: Concept
alt label: unstable star
broader: variableStar
definition: intrinsic variable star
narrower: HerbigHaroObject
narrower: magneticVariableStar
narrower: pulsatingVariableStar
narrower: spectrumVariableStar
pref label: intrinsic variable star

inverseComptonEffect
type: Concept
definition: inverse Compton effect
pref label: inverse Compton effect
related: cosmicRay
related: electron
related: highEnergyAstrophysics
related: photon

inverseComptonScattering
type: Concept
definition: inverse Compton scattering
pref label: inverse Compton scattering
related: ComptonScattering
related: electron
related: photon

inverseMaser
type: Concept
definition: inverse maser
pref label: inverse maser
related: maser

iodineCell
type: Concept
broader: opticalFilter
broader: radialVelocity
definition: iodine cell
history note: FVH: new (2007-OCT-25)
pref label: iodine cell

iodine
type: Concept
alt label: I
broader: fundamentalChemicalElement
definition: iodine (atomic number 53)
history note: FVH: new (2007-OCT-25)
pref label: iodine

ionComposition
type: Concept
definition: ion composition
pref label: ion composition
related: ion

ionDensity
type: Concept
definition: ion density
pref label: ion density
related: ion
related: ionization

ion
type: Concept
alt label: charged particle
broader: compositeParticle
broader: particle
definition: ion
narrower: hydroxylRadical
pref label: ion
related: PaulTrap
related: SahaEquation
related: collisionalExcitation
related: collisionalPlasma
related: ionComposition
related: ionDensity
related: ionPlasmaWave
related: ionizedGas
related: plasma
related: plasmaCloud
related: plasmaJet
related: polarizationChargeSeparation
related: radical
related: thermionicEmission

ionizationEquilibrium
type: Concept
alt label: ionisation equilibrium UK
definition: ionization equilibrium
pref label: ionization equilibrium
related: ionization

ionization
type: Concept
alt label: ionisation UK
definition: ionization
narrower: photoionization
pref label: ionization
related: SchwarzschildMetric
related: StromgrenSphere
related: corona
related: ionDensity
related: ionizationEquilibrium
related: shock

ionizedGas
type: Concept
broader: gas
definition: ionized gas
narrower: HIi
pref label: ionized gas
related: StromgrenSphere
related: collisionalExcitation
related: ion
related: plasma

ionizingShockWave
type: Concept
broader: shockWave
definition: ionizing shock wave
pref label: ionizing shock wave

ionosphere
type: Concept
definition: ionosphere
pref label: ionosphere
related: DLayer
related: ELayer
related: EarthAtmosphere
related: FLayer
related: exosphere
related: ionosphericScintillation
related: mesopause
related: radioAbsorption
related: thermosphere
related: upperAtmosphere

ionosphericScintillation
type: Concept
broader: scintillation
definition: ionospheric scintillation
pref label: ionospheric scintillation
related: interplanetaryScintillation
related: interstellarScintillation
related: ionosphere
related: radioSource

ionPlasmaWave
type: Concept
definition: ion plasma wave
pref label: ion plasma wave
related: ion
related: plasmaWave

ionTemperature
type: Concept
broader: temperature
definition: ion temperature
pref label: ion temperature

IrasGalaxy
type: Concept
broader: infraredGalaxy
definition: IRAS galaxy
pref label: IRAS galaxy
related: IrasSatellite

IrasSatellite
type: Concept
alt label: IRAS
broader: infraredObservatory
broader: spaceObservatory
definition: InfraRed Astronomical Satellite
history note: FVH: new, because of IRAS_galaxy (2007-NOV-1)
pref label: IRAS satellite
related: IrasGalaxy
related: infraredRadiation

iridium
type: Concept
alt label: Ir
broader: fundamentalChemicalElement
definition: iridium (atomic number 77)
history note: FVH: new (2007-OCT-25)
pref label: iridium

iron
type: Concept
alt label: Fe
broader: fundamentalChemicalElement
definition: iron (atomic number 26)
history note: FVH: new (2007-OCT-25)
pref label: iron
related: ironMeteorite

ironMeteorite
type: Concept
broader: meteorite
definition: iron meteorite
pref label: iron meteorite
related: iron

irradiance
type: Concept
definition: irradiance
pref label: irradiance
related: radiation

irregularGalaxy
type: Concept
broader: galaxy
definition: irregular galaxy
narrower: IGalaxy
narrower: MagellanicCloud
pref label: irregular galaxy

irregularVariableStar
type: Concept
broader: lateTypeGiant
broader: pulsatingVariableStar
broader: variableStar
definition: irregular variable star
narrower: MiraVariableStar
narrower: RCoronaeBorealisStar
narrower: RvTauriStar
narrower: RwAurigaeStar
narrower: TTauriStar
narrower: UuHerculisStar
narrower: dwarfCepheid
narrower: gammaCassiopeiaeStar
narrower: softGammaRayRepeater
pref label: irregular variable star
related: TAssociation
related: lateTypeSupergiant
related: semiRegularVariableStar
related: supergiant

isophotalDiameter
type: Concept
broader: angularDiameter
broader: diameter
definition: isophotal diameter
history note: ES: new (2007-OCT-11)
pref label: isophotal diameter
related: galaxy
related: isophot
related: luminosityDistribution
related: surfacePhotometry

isophot
type: Concept
definition: isophot
pref label: isophot
related: contourMap
related: isophotalDiameter
related: luminosityDistribution
related: surfacePhotometry

isothermalSphere
type: Concept
broader: massDistribution
definition: isothermal mass-profile
history note: FVH: new (2007-OCT-5)
pref label: isothermal sphere
related: BurkertProfile
related: NavarroFrenkWhiteProfile
related: exponentialProfile

isotope
type: Concept
broader: chemicalElement
definition: isotope
pref label: isotope
related: deuterium
related: tritium

isotopicAbundance
type: Concept
broader: abundance
definition: isotopic abundance
pref label: isotopic abundance
related: isotopicComposition

isotopicComposition
type: Concept
definition: isotopic composition
pref label: isotopic composition
related: isotopicAbundance

isotropy
type: Concept
definition: isotropy
pref label: isotropy
related: anisotropy
related: opticalProperty

Jansky
type: Concept
definition: Jansky
pref label: Jansky
related: radioRadiation
scope note: radio flux density unit

JeansLength
type: Concept
definition: Jeans length
pref label: Jeans length
related: JeansMass
related: gravity
related: starFormation

JeansMass
type: Concept
definition: Jeans mass
pref label: Jeans mass
related: JeansLength

jet
type: Concept
alt label: astrophysical jet
broader: massLoss
definition: jet
narrower: plasmaJet
narrower: radioJet
pref label: jet
related: comet
related: hydrodynamics
related: radioSource

JMagnitude
type: Concept
broader: apparentMagnitude
definition: J magnitude
pref label: J magnitude
related: infraredPhotometry
related: nearInfraredRadiation

JohnsonNoise
type: Concept
definition: Johnson noise
pref label: Johnson noise
related: thermalRadiation

JohnsonPhotometry
type: Concept
alt label: Johnson-Morgan filter system
alt label: UBV photometry
alt label: UBVRI photometry
alt label: UBVRIJKL photometry
alt label: three-color photometry
broader: broadBandPhotometry
broader: photometricSystem
definition: Johnson photometry
pref label: Johnson photometry
related: BMagnitude
related: BesselPhotometry
related: BvPhotometry
related: CapePhotometry
related: CapeRiPhotometry
related: IMagnitude
related: KronCousinsPhotometry
related: RMagnitude
related: UMagnitude
related: VMagnitude
related: eRegion
related: fRegion
related: twoColorPhotometry

JovianPlanet
type: Concept
broader: outerPlanet
definition: Jovian planet
narrower: Jupiter
narrower: Neptune
narrower: Saturn
narrower: Uranus
pref label: Jovian planet

JulianCalendar
type: Concept
broader: calendar
definition: Julian calendar
pref label: Julian calendar
related: GregorianCalendar
related: JulianDate
related: JulianEpoch

JulianDate
type: Concept
alt label: J.D.
alt label: JD
definition: Julian Date
narrower: heliocentricJulianDate
pref label: Julian Date
related: JulianCalendar
related: epoch
related: time

JulianEpoch
type: Concept
broader: epoch
broader: standardEpoch
definition: Julian epoch
pref label: Julian epoch
related: BesselianEpoch
related: JulianCalendar
related: time

jumpCondition
type: Concept
definition: jump condition
pref label: jump condition
related: shockWave

Jupiter
type: Concept
broader: JovianPlanet
broader: planet
definition: Jupiter
history note: FVH: new (2007-SEP-24)
pref label: Jupiter
related: SolarSystem

kappaMechanism
type: Concept
definition: kappa mechanism
pref label: kappa mechanism
related: Cepheid
related: HeIiIonizationZone
related: ZzCetiStar
related: deltaScutiStar
related: pulsatingVariableStar

KapteynSelectedArea
type: Concept
definition: Kapteyn selected area
narrower: eRegion
narrower: fRegion
pref label: Kapteyn selected area
related: CapePhotometry
related: StromgrenPhotometry

KCorona
type: Concept
alt label: K-corona
broader: corona
definition: K corona
pref label: K corona
related: solarCorona

kCorrection
type: Concept
alt label: k-term
definition: k-correction
pref label: k correction
related: redshift

KDwarf
type: Concept
broader: KStar
broader: dwarf
broader: lateTypeDwarf
definition: K dwarf star
pref label: K dwarf
related: KSubdwarf

KellnerEyepiece
type: Concept
broader: eyepiece
definition: Kellner eyepiece
pref label: Kellner eyepiece

Kelvin
type: Concept
broader: absoluteTemperatureScale
definition: Kelvin
pref label: Kelvin
related: celsiusTemperatureScale
related: temperatureScale
scope note: ES: moved absolute_temperature_scale from RT to BT (2007-OCT-8)
scope note: absolute temperature scale units

KelvinTimescale
type: Concept
definition: Kelvin timescale
pref label: Kelvin timescale
related: HelmholtzKelvinContraction

KeplerianOrbit
type: Concept
broader: orbit
definition: Keplerian orbit
pref label: Keplerian orbit
related: celestialMechanics

KerrBlackHole
type: Concept
broader: blackHole
definition: Kerr black hole
pref label: Kerr black hole
related: stellarEvolution

KGiant
type: Concept
broader: KStar
broader: lateTypeGiant
definition: K giant star
pref label: K giant
related: KSubgiant

kinematicParallax
type: Concept
broader: parallax
definition: kinematic parallax
pref label: kinematic parallax
related: dynamicalParallax
related: movingClusterParallax

kinematics
type: Concept
definition: kinematics
narrower: acceleration
pref label: kinematics
related: GalacticRotation
related: GalacticStructure
related: angularMomentum
related: galaxyRotationCurve
related: galaxyStructure
related: properMotion
related: radialVelocity
related: velocity

kineticEnergy
type: Concept
broader: energy
definition: kinetic energy
pref label: kinetic energy
related: potentialEnergy

KirkwoodGap
type: Concept
broader: resonanceGap
definition: Kirkwood gap
pref label: Kirkwood gap
related: asteroid

KLine
type: Concept
broader: FraunhoferLine
broader: HAndKLine
broader: calciumLine
definition: K line
pref label: K line
related: HLine
related: WilsonBappuEffect

KMagnitude
type: Concept
broader: apparentMagnitude
definition: K magnitude
pref label: K magnitude
related: infraredPhotometry
related: nearInfraredRadiation

KramersOpacity
type: Concept
broader: opacity
definition: Kramers opacity
pref label: Kramers opacity
related: RosselandOpacity

KreutzSungrazer
type: Concept
alt label: sungrazer
broader: comet
definition: Kreutz sungrazer
pref label: Kreutz sungrazer
related: SolarSystem

KronCousinsPhotometry
type: Concept
alt label: Kron Cousins photometry
alt label: Kron-Cousins R,I photometry
broader: broadBandPhotometry
broader: photometricSystem
definition: Kron-Cousins photometry
history note: FVH: new (2007-SEP-21)
pref label: Kron-Cousins photometry
related: IMagnitude
related: JohnsonPhotometry
related: RMagnitude

KruskalDiagram
type: Concept
definition: Kruskal diagram
pref label: Kruskal diagram
related: blackHole

krypton
type: Concept
alt label: Kr
broader: fundamentalChemicalElement
definition: krypton (atomic number 36)
history note: FVH: new (2007-OCT-25)
pref label: krypton

KStar
type: Concept
broader: lateTypeStar
definition: K star
narrower: KDwarf
narrower: KGiant
narrower: KSubdwarf
narrower: KSubgiant
narrower: KSupergiant
pref label: K star
related: spectralType

KSubdwarf
type: Concept
broader: KStar
broader: subdwarf
definition: K subdwarf star
pref label: K subdwarf
related: KDwarf

KSubgiant
type: Concept
broader: KStar
broader: subgiant
definition: K subgiant star
pref label: K subgiant
related: KGiant

KSupergiant
type: Concept
broader: KStar
broader: lateTypeSupergiant
broader: supergiant
definition: K supergiant star
pref label: K supergiant

LagrangianPoint
type: Concept
alt label: libration point
definition: Lagrangian point
pref label: Lagrangian point
related: celestialMechanics
related: gravitation
related: gravitationalField

lambdaEridaniStar
type: Concept
broader: BeStar
broader: pulsatingVariableStar
definition: lambda Eridani star
pref label: lambda eridani star

lamp
type: Concept
definition: lamp
narrower: comparisonLamp
narrower: flatFieldLamp
pref label: lamp
related: calibration
related: electromagneticRadiation

lanthanum
type: Concept
alt label: La
broader: fundamentalChemicalElement
broader: rareEarth
definition: lanthanum (atomic number 57)
history note: FVH: new (2007-OCT-25)
pref label: lanthanum

LargeMagellanicCloud
type: Concept
alt label: LMC
broader: MagellanicCloud
definition: Large Magellanic Cloud
pref label: Large Magellanic Cloud
related: SmallMagellanicCloud

largeScaleStructure
type: Concept
change note: FVH: added RT COSMOLOGY (2007-SEP-21)
definition: large scale structure
pref label: large scale structure
related: cosmicString
related: cosmology
related: universe

laser
type: Concept
definition: laser
pref label: laser
related: coherence
related: electronPumping
related: lightCoherence
related: lunarLaserRanging
related: maser
related: opticalRadar
related: populationInversion
related: satelliteLaserRanging
related: stimulatedEmission

laserRanging
type: Concept
definition: laser ranging
narrower: lunarLaserRanging
narrower: satelliteLaserRanging
pref label: laser ranging
related: opticalRadar

lateTypeDwarf
type: Concept
alt label: cool dwarf star
alt label: late type dwarf star
broader: dwarf
broader: lateTypeStar
broader: lowLuminosityStar
definition: late-type dwarf star
narrower: KDwarf
narrower: LDwarf
narrower: MDwarf
narrower: brownDwarf
narrower: redDwarfFlareStar
pref label: late-type dwarf

lateTypeGalaxy
type: Concept
alt label: late type galaxy
broader: galaxy
definition: late-type galaxy
pref label: late-type galaxy
related: spiralGalaxy

lateTypeGiant
type: Concept
alt label: cool giant star
alt label: late type giant star
broader: giant
broader: lateTypeStar
definition: late-type giant star
narrower: KGiant
narrower: MGiant
narrower: MiraVariableStar
narrower: carbonStar
narrower: heavyMetalStar
narrower: irregularVariableStar
narrower: semiRegularVariableStar
pref label: late-type giant
related: asymptoticGiantBranch
related: funneling
related: postAsymptoticGiantBranch
related: redGiantTip

lateTypeStar
type: Concept
alt label: cool star
alt label: late type star
broader: star
definition: late-type star
narrower: KStar
narrower: MStar
narrower: NStar
narrower: RStar
narrower: SStar
narrower: lateTypeDwarf
narrower: lateTypeGiant
narrower: lateTypeSubdwarf
narrower: lateTypeSupergiant
pref label: late-type star
related: WilsonBappuEffect
related: molecularBand
related: molecularLine
related: molecularSpectrum

lateTypeSubdwarf
type: Concept
alt label: cool subdwarf star
broader: lateTypeStar
broader: lowLuminosityStar
broader: subdwarf
definition: late-type subdwarf
narrower: LSubdwarf
narrower: brownDwarf
pref label: late-type subdwarf

lateTypeSupergiant
type: Concept
alt label: cool supergiant star
broader: lateTypeStar
broader: supergiant
definition: late-type supergiant star
narrower: KSupergiant
narrower: MSupergiant
narrower: RvTauriStar
pref label: late-type supergiant
related: irregularVariableStar
related: longPeriodVariableStar

lateTypeVariableStar
type: Concept
definition: late-type variable star
narrower: MeVariableStar
pref label: late-type variable star
related: MeStar

latitudeDetermination
type: Concept
definition: latitude determination
narrower: latitudeVariation
pref label: latitude determination
related: ChandlerWobble
related: astrometry
scope note: on Earth surface

latitude
type: Concept
definition: latitude
narrower: Declination
narrower: GalacticLatitude
narrower: eclipticLatitude
narrower: supergalacticLatitude
pref label: latitude
scope note: on celestial sphere

latitudeVariation
type: Concept
broader: latitudeDetermination
definition: latitude variation
pref label: latitude variation
related: ChandlerWobble
related: polarMotion
scope note: on Earth surface

lawrencium
type: Concept
alt label: Lr
broader: fundamentalChemicalElement
definition: lawrencium (atomic number 103)
history note: FVH: new (2007-OCT-25)
pref label: lawrencium

LbVariableStar
type: Concept
broader: giant
definition: Lb variable star
pref label: Lb variable star

LcVariableStar
type: Concept
definition: Lc variable star
pref label: Lc variable star
related: supergiant

LDwarf
type: Concept
broader: brownDwarf
broader: lateTypeDwarf
definition: L dwarf
history note: FVH: new (2007-OCT-2)
pref label: L dwarf
related: LSubdwarf
related: spectralType
related: titaniumOxide

lead
type: Concept
alt label: Pb
broader: fundamentalChemicalElement
definition: lead (atomic number 82)
history note: FVH: new (2007-OCT-25)
pref label: lead

LemaitreUniverse
type: Concept
broader: cosmology
definition: Lemaitre universe
pref label: Lemaitre universe
related: BigBangTheory

lensAntenna
type: Concept
alt label: lens antennas
broader: antenna
definition: lens antenna
pref label: lens antenna

lensDesign
type: Concept
definition: lens design
pref label: lens design
related: lens

lens
type: Concept
broader: opticalComponent
definition: lens
narrower: cameraLens
narrower: correctorPlate
narrower: fieldCorrector
narrower: primaryLens
pref label: lens
related: antireflectionCoating
related: catadioptricSystem
related: coating
related: collimator
related: dioptricSystem
related: eyepiece
related: figuring
related: glass
related: lensDesign
related: opticalAberration
related: opticalInstrument
related: opticalMaterial
related: opticalSurface
related: polishing
related: refraction
related: refractiveIndex

lenticularGalaxy
type: Concept
alt label: S0 galaxy
broader: diskGalaxy
broader: galaxy
definition: lenticular galaxy
pref label: lenticular galaxy
related: ansa

lepton
type: Concept
broader: elementaryParticle
broader: particle
definition: lepton
narrower: electron
narrower: muon
narrower: neutrino
narrower: positron
pref label: lepton
related: boson
related: quark

LGalaxy
type: Concept
broader: galaxy
definition: low surface-brightness galaxy (Yerkes classification scheme)
pref label: L galaxy
related: YerkesClassification
related: surfaceBrightness

libration
type: Concept
alt label: physical libration
definition: libration
pref label: libration
related: Moon

life
type: Concept
definition: life
narrower: extraterrestrialLife
pref label: life
related: anthropicPrinciple
related: origin

lightAbsorption
type: Concept
broader: absorption
definition: light absorption
pref label: light absorption
related: atmosphericExtinction
related: electromagneticRadiation
related: interstellarAbsorption
related: interstellarReddening
related: lightScattering
related: visibleRadiation

lightCoherence
type: Concept
broader: coherence
definition: light coherence
pref label: light coherence
related: laser

lightCone
type: Concept
definition: light cone
narrower: futureLightCone
narrower: pastLightCone
pref label: light cone
related: velocityOfLight

lightCurve
type: Concept
broader: photometricElement
definition: light curve
pref label: light curve
related: magnitude
related: maximum
related: minimum
related: period
related: phaseShift
related: phaseWave
related: variableStar
related: velocityCurve

lightEmission
type: Concept
definition: light emission
narrower: photoluminescence
pref label: light emission
related: aurora
related: chemiluminescence
related: continuousSpectrum
related: emissionSpectrum
related: luminescence

lightInterference
type: Concept
broader: interferenceWave
definition: light interference
pref label: light interference
related: electromagneticRadiation
related: opticalFilm
related: opticalFilter
related: opticalInterferometry
related: visibleRadiation

lightPolarization
type: Concept
alt label: polarization wave
definition: light polarization
narrower: XRayPolarization
narrower: circularPolarization
narrower: planePolarization
pref label: light polarization
related: FaradayEffect
related: electromagneticRadiation
related: opticalProperty
related: polarimetry
related: polarizedLight
related: polarizedRadiation
related: radiationScattering
related: stokesParameter

lightPollution
type: Concept
broader: pollution
definition: light pollution
pref label: light pollution
related: airPollution
related: siteProtection

lightScattering
type: Concept
broader: radiationScattering
broader: scattering
definition: light scattering
narrower: ComptonScattering
narrower: RayleighScattering
narrower: ThomsonScattering
pref label: light scattering
related: RamanSpectrum
related: afterglow
related: atmosphericExtinction
related: brillouinSpectrum
related: electromagneticRadiation
related: halo
related: interstellarReddening
related: lightAbsorption
related: luminescence
related: visibleRadiation
related: zodiacalLight

lightYear
type: Concept
definition: light year
pref label: light year
related: distance
related: parsec
related: velocityOfLight
related: year

limbBrightening
type: Concept
definition: limb brightening
pref label: limb brightening
related: atmosphere
related: limbDarkening
related: stellarAtmosphere
related: temperature

limbDarkening
type: Concept
definition: limb darkening
pref label: limb darkening
related: atmosphere
related: limbBrightening
related: solarAtmosphere
related: stellarAtmosphere
related: temperature

limitingMagnitude
type: Concept
definition: limiting magnitude
pref label: limiting magnitude
related: detector
related: precision
related: sensitivity
related: signalDetection
related: signalToNoiseRatio

linearityCalibration
type: Concept
broader: calibration
definition: linearity calibration
history note: FVH: new (2007-OCT-3)
pref label: linearity calibration

lineBlanketing
type: Concept
definition: line blanketing
pref label: line blanketing
related: metalLine
related: spectralLine
related: ultravioletRadiation

lineBlending
type: Concept
definition: line blending
pref label: line blending
related: spectralLine
related: spectralResolution

lineBlocking
type: Concept
definition: line blocking
pref label: line blocking
scope note: see under line blanketing

lineBroadening
type: Concept
alt label: spectral line broadening
definition: line broadening
narrower: DopplerBroadening
narrower: StarkBroadening
narrower: collisionBroadening
narrower: naturalLineBroadening
narrower: pressureBroadening
pref label: line broadening
related: ZeemanSplitting
related: convection
related: equivalentWidth
related: instrumentalProfile
related: lineFormation
related: lineWidth
related: naturalLineWidth
related: spectralLine
related: stellarAtmosphere
related: turbulenceStarAtmosphere

lineFormation
type: Concept
alt label: spectral line formation
definition: line formation
pref label: line formation
related: absorptionLine
related: dampingConstant
related: emissionLine
related: gValue
related: gfValue
related: lineBroadening
related: oscillatorStrength
related: solarAtmosphere
related: spectralLine
related: stellarAtmosphere
related: transitionProbability

lineIdentification
type: Concept
definition: line identification
pref label: line identification
related: absorptionLine
related: emissionLine
related: spectralLine

lineIntensitite
type: Concept
definition: line intensitite
pref label: line intensitite
related: emissionLine
related: spectralLine

lineOfSight
type: Concept
broader: location
definition: line-of-sight
history note: FVH: new (2007-SEP-21)
pref label: line of sight
related: locationBehind
related: locationBetween
related: locationInFront

lineProfile
type: Concept
broader: profile
definition: line profile
narrower: PCygniLineProfile
narrower: instrumentalProfile
pref label: line profile
related: absorptionLine
related: emissionLine
related: residualIntensity
related: spectralLine

lineRatio
type: Concept
definition: line ratio
pref label: line ratio
related: absorptionLine
related: emissionLine
related: spectralLine

linerGalaxy
type: Concept
broader: emissionLineGalaxy
definition: liner galaxy
history note: FVH: new (2007-SEP-21)
pref label: liner galaxy
related: SeyfertGalaxy
related: quasar

lineShift
type: Concept
alt label: spectral line shift
definition: line shift
narrower: blueshift
narrower: redshift
pref label: line shift
related: DopplerEffect
related: ZeemanSplitting
related: radialVelocity

lineSpectrum
type: Concept
definition: line spectrum
narrower: absorptionSpectrum
narrower: emissionSpectrum
pref label: line spectrum
related: VoigtProfile
related: pressureBroadening
related: ultravioletLine

lineWidth
type: Concept
alt label: spectral line width
definition: line width
narrower: equivalentWidth
narrower: naturalLineWidth
pref label: line width
related: DopplerBroadening
related: MilneEddingtonApproximation
related: TullyFisherRelation
related: gValue
related: gfValue
related: instrumentalProfile
related: lineBroadening
related: oscillatorStrength
related: spectralType
related: stellarAtmosphere
related: surfaceGravity
related: transitionProbability

lithium
type: Concept
alt label: Li
broader: fundamentalChemicalElement
definition: lithium (atomic number 3)
history note: FVH: new (2007-OCT-25)
pref label: lithium
related: lithiumPoorStar
related: lithiumStar

lithiumPoorStar
type: Concept
alt label: lithium poor star
broader: metalPoorStar
definition: lithium-poor star
pref label: lithium-poor star
related: lithium

lithiumStar
type: Concept
alt label: Li star
alt label: lithium rich star
alt label: lithium-rich star
broader: star
definition: lithium star
pref label: lithium star
related: giant
related: lithium

lithosphere
type: Concept
definition: lithosphere
pref label: lithosphere
related: mantle
related: planet

LMagnitude
type: Concept
broader: apparentMagnitude
definition: L magnitude
pref label: L magnitude
related: infraredPhotometry
related: nearInfraredRadiation

lobe
type: Concept
broader: radioStructure
definition: lobe
pref label: lobe
related: radioSource
scope note: radio source feature

LocalGroup
type: Concept
broader: galaxyGroup
broader: nearbyGalaxy
definition: Local Group of galaxies
narrower: MagellanicCloud
narrower: MilkyWayGalaxy
pref label: Local Group
related: brightGalaxy

LocalStandardOfRest
type: Concept
alt label: L.S.R.
alt label: LSR
definition: Local Standard of Rest
pref label: Local Standard of Rest
related: Sun
related: orbit
related: peculiarMotion
related: peculiarVelocity
related: properMotion
related: stellarMotion

LocalSupercluster
type: Concept
broader: galaxyCluster
definition: Local Supercluster of galaxies
pref label: Local Supercluster
related: GreatAttractor
related: galaxy

localThermodynamicEquilibrium
type: Concept
alt label: LTE
broader: thermodynamicEquilibrium
definition: local thermodynamic equilibrium
pref label: local thermodynamic equilibrium
related: nonLteTransfer
related: thermalEquilibrium
related: thermalInstability
related: thermalStability
related: thermodynamics

locationBehind
type: Concept
broader: location
definition: location behind something else
history note: FVH: new (2007-SEP-21)
pref label: location behind
related: lineOfSight
related: locationBetween
related: locationInFront

locationBetween
type: Concept
broader: location
definition: location between
history note: FVH: new (2007-SEP-21)
pref label: location between
related: lineOfSight
related: locationBehind
related: locationInFront

locationInFront
type: Concept
broader: location
definition: location in front of something else
history note: FVH: new (2007-SEP-21)
pref label: location in front
related: lineOfSight
related: locationBehind
related: locationBetween

location
type: Concept
definition: having to do with cosmic location
history note: FVH: new (2007-SEP-21)
narrower: lineOfSight
narrower: locationBehind
narrower: locationBetween
narrower: locationInFront
pref label: location

logGValue
type: Concept
broader: gValue
definition: log(g) value
history note: ES: new (2007-OCT-8)
history note: logarithm reference needed!
pref label: log g value
related: gfValue

longBaselineInterferometer
type: Concept
broader: interferometer
broader: radioInterferometer
definition: long baseline interferometer
pref label: long baseline interferometer
related: opticalInterferometer
related: veryLongBaselineInterferometer

longBaselineInterferometry
type: Concept
broader: interferometry
broader: radioInterferometry
definition: long baseline interferometry
pref label: long baseline interferometry
related: opticalInterferometry
related: radioAstrometry
related: veryLongBaselineInterferometry

longitude
type: Concept
definition: longitude
narrower: GalacticLongitude
narrower: RightAscension
narrower: eclipticLongitude
narrower: supergalacticLongitude
pref label: longitude
scope note: on celestial sphere

longPeriodComet
type: Concept
broader: comet
definition: long period comet
pref label: long period comet

longPeriodVariableStar
type: Concept
broader: pulsatingVariableStar
definition: long period variable star
narrower: MiraVariableStar
narrower: RvTauriStar
narrower: SVulpeculaeStar
narrower: WzSagittaeStar
pref label: long period variable star
related: lateTypeSupergiant

longSlit
type: Concept
broader: spectrographSlit
definition: long slit
history note: FVH: new (2007-OCT-3)
pref label: long slit

longSlitSpectrum
type: Concept
change note: FVH: added RT SPECTROGRAPH_SLITS (2007-SEP-21)
definition: long slit spectrum
pref label: long slit spectrum
related: spectrographSlit
related: threeDimensionalSpectrum
related: twoDimensionalSpectrum

loop
type: Concept
definition: loop
pref label: loop
scope note: combine with other terms

lowLuminosityStar
type: Concept
alt label: low luminosity star
broader: star
definition: low-luminosity star
narrower: lateTypeDwarf
narrower: lateTypeSubdwarf
pref label: low-luminosity star
related: dwarf
related: lowMassStar

lowMassStar
type: Concept
alt label: low mass star
broader: star
change note: FVH+ES: moved brown_dwarf to RT (2007-OCT-11)
definition: low-mass star
narrower: HzHerculisStar
narrower: blackDwarf
pref label: low-mass star
related: TDwarf
related: brownDwarf
related: dwarf
related: lowLuminosityStar
related: lowMassXRayBinaryStar

lowMassXRayBinaryStar
type: Concept
alt label: LMXB
broader: XRayBinaryStar
definition: low-mass X-ray binary star
pref label: low-mass X-ray binary star
related: accretionDisk
related: cataclysmicVariableStar
related: highMassXRayBinaryStar
related: lowMassStar
related: neutronStar

lowState
type: Concept
definition: photometric low state of variable object
history note: FVH: new (2007-OCT-8)
pref label: low-state
related: highState
related: outburst
related: variability
related: variableSource

lowTemperaturePlasma
type: Concept
broader: plasma
definition: low temperature plasma
pref label: low-temperature plasma

LSubdwarf
type: Concept
broader: brownDwarf
broader: lateTypeSubdwarf
broader: subdwarf
definition: L subdwarf
history note: FVH: new (2007-OCT-9)
pref label: L subdwarf
related: LDwarf

luminescence
type: Concept
alt label: candoluminescence
definition: luminescence
narrower: chemiluminescence
narrower: thermoluminescence
pref label: luminescence
related: afterglow
related: electromagneticRadiation
related: fluorescence
related: lightEmission
related: lightScattering
related: noctilucentCloud
related: visibleRadiation

luminosityClassification
type: Concept
broader: classification
definition: luminosity classification
pref label: luminosity classification
related: dwarf
related: giant
related: luminosityClass
related: spectralClassification
related: spectralType
related: subgiant
related: surfaceGravity

luminosityClass
type: Concept
broader: MkClassification
definition: luminosity class
pref label: luminosity class
related: luminosity
related: luminosityClassification
related: spectralType
scope note: see: luminosity classification

luminosityDispersionRelation
type: Concept
broader: correlation
definition: luminosity-dispersion relation
history note: FVH: new (2007-OCT-9)
narrower: FaberJacksonRelation
narrower: fundamentalPlane
pref label: luminosity-dispersion relation
related: luminosity
related: velocityDispersion

luminosityDistribution
type: Concept
definition: luminosity distribution
pref label: luminosity distribution
related: brightnessTemperature
related: isophot
related: isophotalDiameter

luminosityFunction
type: Concept
definition: luminosity function
pref label: luminosity function
related: galaxy
related: galaxyCluster
related: starCluster
related: stellarEvolution

luminosity
type: Concept
change note: FVH: removed UF absolute_intensity as unphysical misnomer (2007-SEP-24)
definition: luminosity
narrower: XRayLuminosity
narrower: ultravioletLuminosity
pref label: luminosity
related: HertzsprungRussellDiagram
related: MkClassification
related: absoluteMagnitude
related: brightness
related: flux
related: fluxDensity
related: intensity
related: luminosityClass
related: luminosityDispersionRelation
related: massToLightRatio
related: surfaceGravity

luminousArc
type: Concept
broader: arc
broader: gravitationallyLensedSource
change note: FVH: changed UF arc to BT ARCS and QUASARS to CLUSTERS_OF_GALAXIES (2007-OCT-1)
change note: FVH: moved BT arc to RT arc and added BT gravitationally_lensed_source (2007-OCT-8)
definition: luminous arc produced by gravitational lensing
pref label: luminous arc
related: galaxyCluster
related: gravitationalLensing
related: quasar

luminousBlueVariableStar
type: Concept
broader: earlyTypeVariableStar
broader: highLuminosityStar
definition: luminous blue variable star
pref label: luminous blue variable star
related: earlyTypeSupergiant

lunarDome
type: Concept
definition: lunar dome
pref label: lunar dome
related: Moon
related: surfaceOfCelestialBody

lunarEclipse
type: Concept
broader: eclipse
definition: lunar eclipse
pref label: lunar eclipse
related: Moon
related: SarosCycle
related: Sun
related: penumbra
related: umbra

lunarLaserRanging
type: Concept
broader: laserRanging
definition: lunar laser ranging
pref label: lunar laser ranging
related: Moon
related: laser
related: opticalRadar
related: satelliteLaserRanging

lunar
type: Concept
definition: lunar
pref label: lunar
scope note: combine lunar or Moon with other terms; also see Moon

lunarOccultation
type: Concept
broader: occultation
definition: occultation by the Moon
history note: FVH: new (2007-OCT-8)
pref label: lunar occultation
related: Moon

lunarPhase
type: Concept
alt label: phase Moon
definition: phase of the Moon
pref label: lunar phase
related: SarosCycle
related: illumination
related: metonicCycle
related: phaseAngle
related: phaseDefect
related: phaseEffect
related: terminatorLine

lunarTheory
type: Concept
definition: lunar theory
pref label: lunar theory
related: EarthMoonSystem
related: Moon
related: celestialMechanics

lutetium
type: Concept
alt label: Lu
broader: fundamentalChemicalElement
broader: rareEarth
definition: lutetium (atomic number 71)
history note: FVH: new (2007-OCT-25)
pref label: lutetium

LymanAlpha
type: Concept
broader: LymanSeries
broader: resonanceLine
definition: Lyman alpha
pref label: Lyman alpha
related: LymanAlphaForest

LymanAlphaForest
type: Concept
definition: Lyman alpha forest
pref label: Lyman alpha forest
related: LymanAlpha
related: absorptionLine
related: intergalacticAbsorption
related: quasar
related: redshift

LymanBeta
type: Concept
broader: LymanSeries
definition: Lyman beta
pref label: Lyman beta

LymanContinuum
type: Concept
broader: hydrogenSpectrum
definition: Lyman continuum
pref label: Lyman continuum
related: ultravioletRadiation

LymanSeries
type: Concept
broader: hydrogenSpectrum
definition: Lyman series
narrower: LymanAlpha
narrower: LymanBeta
pref label: Lyman series
related: BalmerSeries
related: BrackettSeries
related: PaschenSeries
related: PfundSeries
related: ultravioletRadiation

macroSpicule
type: Concept
broader: spicule
definition: macro spicule
pref label: macro spicule
related: Sun
related: chromosphere

macroturbulence
type: Concept
broader: turbulenceEarthAtmosphere
broader: turbulenceStarAtmosphere
definition: macroturbulence
pref label: macroturbulence
related: atmosphere
related: stellarStructure

MagellanicCloud
type: Concept
alt label: Clouds of Magellan
broader: LocalGroup
broader: galaxy
broader: irregularGalaxy
broader: nearbyGalaxy
definition: Magellanic cloud
narrower: LargeMagellanicCloud
narrower: SmallMagellanicCloud
pref label: Magellanic cloud
related: MagellanicStream

MagellanicStream
type: Concept
definition: Magellanic stream
pref label: Magellanic stream
related: MagellanicCloud

magnesium
type: Concept
alt label: Mg
broader: fundamentalChemicalElement
definition: magnesium (atomic number 12)
history note: FVH: new (2007-OCT-25)
pref label: magnesium

magnetar
type: Concept
broader: magneticStar
broader: neutronStar
definition: magnetar
history note: ES: new (2007-OCT-8)
narrower: softGammaRayRepeater
pref label: magnetar

magneticAnomaly
type: Concept
broader: anomaly
definition: magnetic anomaly
pref label: magnetic anomaly
related: gravityAnomaly
related: magneticProperty

magneticDisturbances
type: Concept
definition: magnetic disturbances
pref label: magnetic disturbances
related: aurora
related: magneticProperty

magneticField
type: Concept
definition: magnetic field
narrower: emergingFlux
narrower: geomagneticField
narrower: interplanetaryMagneticField
narrower: interstellarMagneticField
pref label: magnetic field
related: PaschenBackEffect
related: dynamoTheory
related: force
related: magneticMonopole
related: magneticPole
related: magneticProperty
related: magneticVariableStar
related: magnetohydrodynamics
related: magnetosphere
related: paleomagnetism
related: sunspot

magneticMonopole
type: Concept
definition: magnetic monopole
pref label: magnetic monopole
related: magneticField
related: magneticPole

magneticPole
type: Concept
definition: magnetic pole
pref label: magnetic pole
related: aurora
related: magneticField
related: magneticMonopole
related: magneticStorm
related: magneticVariableStar

magneticProperty
type: Concept
broader: property
definition: magnetic property
pref label: magnetic property
related: magneticAnomaly
related: magneticDisturbances
related: magneticField
related: magneticStar

magneticStar
type: Concept
alt label: cobalt star
broader: peculiarStar
definition: magnetic star
narrower: AmStar
narrower: BpStar
narrower: magnetar
narrower: magneticVariableStar
narrower: manganeseStar
narrower: mercuryManganeseStar
pref label: magnetic star
related: ApStar
related: cobalt
related: magneticProperty
related: obliqueRotator
related: spectrumVariableStar
related: strontiumStar

magneticStorm
type: Concept
definition: magnetic storm
narrower: magnetosphericSubstorm
pref label: magnetic storm
related: aurora
related: magneticPole
related: magnetosphere
related: solarActivity
related: sunspot

magneticVariableStar
type: Concept
broader: intrinsicVariableStar
broader: magneticStar
definition: magnetic variable star
narrower: AmStar
narrower: SxArietisStar
narrower: alpha2CanumVenaticorumStar
pref label: magnetic variable star
related: ApStar
related: magneticField
related: magneticPole

magnetograph
type: Concept
broader: instrument
definition: magnetograph
pref label: magnetograph

magnetoheliograph
type: Concept
broader: instrument
definition: magnetoheliograph
pref label: magnetoheliograph

magnetohydrodynamics
type: Concept
alt label: MHD
alt label: hydromagnetics
change note: FVH: moved mhd to ALT, ALFVEN_WAVES to NT (2007-SEP-24)
definition: magnetohydrodynamics
narrower: AlfvenWave
pref label: magnetohydrodynamics
related: cosmicElectrodynamics
related: hydrodynamics
related: magneticField
related: plasmaPhysics
related: plasmaWave
related: synchrotronRadiation
related: vanAllenRadiationBelt

magnetoOpticalEffect
type: Concept
alt label: magneto optical effect
definition: magneto-optical effect
narrower: FaradayEffect
narrower: ZeemanSplitting
narrower: polarizationChargeSeparation
pref label: magneto-optical effect

magnetosphere
type: Concept
definition: magnetosphere
pref label: magnetosphere
related: EarthAtmosphere
related: exosphere
related: magneticField
related: magneticStorm
related: magnetosphericSubstorm
related: upperAtmosphere

magnetosphericSubstorm
type: Concept
broader: magneticStorm
definition: magnetospheric substorm
pref label: magnetospheric substorm
related: magnetosphere

magnitude
type: Concept
definition: magnitude
narrower: absoluteMagnitude
narrower: apparentMagnitude
narrower: integratedMagnitude
pref label: magnitude
related: PogsonScale
related: amplitude
related: brightness
related: intensity
related: lightCurve
related: photometry
scope note: also see under apparent magnitude

mainSequence
type: Concept
definition: main sequence
pref label: main sequence
related: HertzsprungRussellDiagram
related: dwarf
related: mainSequenceStar
related: turnoffPoint
related: zeroAgeMainSequence

mainSequenceStar
type: Concept
broader: star
definition: main sequence star
narrower: blueStragglerStar
narrower: dwarf
pref label: main sequence star
related: mainSequence
related: massLuminosityRelation
scope note: only the broad classes are shown below; specific type will be found under these, or from the hierarchical list

majorAxis
type: Concept
broader: semimajorAxis
definition: major axis
pref label: major axis
related: axialRatio
related: minorAxis
scope note: see terms under semimajor axis

MaksutovTelescope
type: Concept
broader: catadioptricSystem
broader: reflectingTelescope
definition: Maksutov telescope
pref label: Maksutov telescope
related: BouwersTelescope
related: SchmidtTelescope
related: wideFieldTelescope

manganese
type: Concept
alt label: Mn
broader: fundamentalChemicalElement
definition: manganese (atomic number 25)
history note: FVH: new (2007-OCT-25)
pref label: manganese
related: manganeseStar
related: mercuryManganeseStar

manganeseStar
type: Concept
broader: ApStar
broader: magneticStar
broader: spectrumVariableStar
definition: manganese star
pref label: manganese star
related: manganese

mantle
type: Concept
definition: mantle
pref label: mantle
related: Earth
related: Moon
related: crust
related: crustalDynamics
related: lithosphere
related: planet

map
type: Concept
definition: map
narrower: XRayMap
narrower: contourMap
pref label: map
related: atlas
related: catalog
related: findingChart
related: photogrammetry
related: planet
related: radarMapping
related: skySurvey
related: starAtlas

maria
type: Concept
definition: maria
pref label: maria
related: Moon
related: surfaceOfCelestialBody

MarkarianGalaxy
type: Concept
broader: emissionLineGalaxy
definition: Markarian galaxy
pref label: Markarian galaxy
related: SeyfertGalaxy
related: peculiarGalaxy

Mars
type: Concept
broader: planet
definition: Mars
history note: FVH: new (2007-SEP-24)
pref label: Mars
related: SolarSystem

mascon
type: Concept
definition: mascon
pref label: mascon
related: Moon
related: gravityAnomaly

maser
type: Concept
definition: maser
narrower: OhMaser
narrower: SiOMaser
narrower: megamaser
narrower: waterMaser
pref label: maser
related: coherence
related: electronPumping
related: interstellarMatter
related: inverseMaser
related: laser
related: populationInversion
related: radioRecombinationLine
related: radioSource
related: stimulatedEmission

massDensity
type: Concept
broader: density
change note: FVH: added NT OMEGA_PARAMETER (2007-SEP-21)
definition: mass-density
pref label: mass density
related: OmegaBaryon
related: OmegaMass
related: OmegaParameter
related: mass

massDistribution
type: Concept
definition: mass distribution
history note: FVH: new (2007-OCT-5)
narrower: BurkertProfile
narrower: NavarroFrenkWhiteProfile
narrower: exponentialProfile
narrower: isothermalSphere
pref label: mass distribution
related: DarkMatter
related: diskGalaxy
related: galaxy
related: galaxyCluster
related: galaxyRotationCurve
related: galaxyStructure
related: gravitationalLensing

massExchange
type: Concept
alt label: exchange of mass
definition: mass-exchange
pref label: mass exchange
related: cataclysmicVariableStar
related: contactBinaryStar
related: eruptiveBinaryStar
related: mass
related: massFlow
related: massLoss
related: massTransfer

massFlow
type: Concept
definition: mass-flow
pref label: mass flow
related: mass
related: massExchange
related: massLoss
related: massTransfer

massFunction
type: Concept
definition: mass-function
pref label: mass function
related: birthRate
related: mass
related: massRatio
related: spectroscopicBinaryStar
related: starCluster
related: starCount

massiveGalaxy
type: Concept
broader: galaxy
definition: massive galaxy
narrower: cDGalaxy
pref label: massive galaxy
related: DGalaxy
related: galaxyCluster

massiveObject
type: Concept
definition: massive object
pref label: massive object
related: SeyfertGalaxy
related: blackHole
related: galacticNucleus

massiveStar
type: Concept
broader: star
definition: massive star
pref label: massive star
related: massLoss
related: supermassiveStar

massLoss
type: Concept
alt label: mass loss
alt label: mass-ejection
definition: mass-loss
narrower: bipolarOutflow
narrower: coronalMassEjection
narrower: jet
narrower: stellarWind
pref label: mass-loss
related: FuOrionisStar
related: PCygniLineProfile
related: WolfRayetStar
related: binaryStar
related: cataclysmicVariableStar
related: circumstellarDisk
related: circumstellarEnvelope
related: circumstellarMatter
related: circumstellarShell
related: corona
related: eruptiveBinaryStar
related: massExchange
related: massFlow
related: massTransfer
related: massiveStar
related: nova
related: planetaryNebula
related: stellarEvolution
related: supernova

massLuminosityRelation
type: Concept
alt label: mass luminosity relation
broader: statisticalRelation
definition: mass-luminosity relation
pref label: mass-luminosity relation
related: mainSequenceStar

mass
type: Concept
definition: mass
narrower: ChandrasekharMass
narrower: ChandrasekharSchoenbergLimit
pref label: mass
related: gravitation
related: initialMassFunction
related: massDensity
related: massExchange
related: massFlow
related: massFunction
related: massToLightRatio
related: momentum
related: spectroscopicBinaryStar
related: surfaceGravity

massRadiusRelation
type: Concept
alt label: mass radius relation
broader: statisticalRelation
definition: mass-radius relation
pref label: mass-radius relation
related: ChandrasekharMass
related: ChandrasekharSchoenbergLimit
related: degenerateStar

massRatio
type: Concept
alt label: mass ratio
definition: mass-ratio
pref label: mass-ratio
related: binaryStar
related: initialMassFunction
related: massFunction

massToLightRatio
type: Concept
definition: mass-to-light ratio
pref label: mass to light ratio
related: galaxy
related: luminosity
related: mass
related: missingMass

massTransfer
type: Concept
alt label: mass transfer
definition: mass-transfer
pref label: mass-transfer
related: accretion
related: convection
related: fluidDynamics
related: massExchange
related: massFlow
related: massLoss

mathematicalAnalysis
type: Concept
definition: mathematical analysis
narrower: differentialEquation
pref label: mathematical analysis
related: catastropheTheory
scope note: combine with other terms

mathematicalModel
type: Concept
change note: FVH: changed COMPUTER_MODELS from U to RT (2007-SEP-21)
definition: mathematical model
pref label: mathematical model
related: computerModel

mathematics
type: Concept
broader: scientificField
definition: mathematics
pref label: mathematics
scope note: combine with other terms

matter
type: Concept
definition: matter
narrower: antimatter
narrower: atom
narrower: circumplanetaryMatter
narrower: circumstellarMatter
narrower: degenerateMatter
narrower: molecule
pref label: matter

MaunderMinimum
type: Concept
definition: Maunder minimum
pref label: Maunder minimum
related: solarActivity
related: sunspotCycle
related: sunspotNumber

maximumEntropyMethod
type: Concept
definition: maximum entropy method
pref label: maximum entropy method
related: FourierAnalysis
related: frequencyAnalysis
related: spectroscopicAnalysis

maximum
type: Concept
broader: photometricElement
definition: maximum
pref label: maximum
related: lightCurve
related: minimum
related: variableStar
related: velocityCurve

MDwarf
type: Concept
broader: MStar
broader: dwarf
broader: lateTypeDwarf
definition: M dwarf star
pref label: M dwarf

meanAnomaly
type: Concept
broader: orbitalAnomaly
definition: mean anomaly
pref label: mean anomaly

meanEquinox
type: Concept
broader: equinox
definition: mean equinox
pref label: mean equinox
related: planet

meanSolarTime
type: Concept
broader: time
definition: mean solar time
pref label: mean solar time
related: UniversalTime
related: civilTime
related: ephemerisTime
related: equationOfTime

measurement
type: Concept
definition: measurement
pref label: measurement
related: determination
related: measuringInstrument
related: metrology
related: quantization
scope note: combine with other terms

measuringInstrument
type: Concept
definition: measuring instrument
narrower: altimeter
narrower: anemometer
narrower: atomicClock
narrower: barometer
narrower: chronometer
narrower: clock
narrower: counter
narrower: densitometer
narrower: heliometer
narrower: microdensitometer
narrower: micrometer
narrower: microphotometer
narrower: monochromator
narrower: proportionalCounter
narrower: radiometer
narrower: rangeFinder
narrower: sensitometer
narrower: weatherStation
narrower: windVane
pref label: measuring instrument
related: calibration
related: measurement

mechanicalComponent
type: Concept
definition: mechanical component
pref label: mechanical component
scope note: combine with other terms

mechanicalProperty
type: Concept
broader: property
definition: mechanical property
pref label: mechanical property
scope note: combine with other terms

mediumBandPhotometry
type: Concept
broader: CcdPhotometry
broader: photoelectricPhotometry
definition: medium-band photometry
narrower: DdoPhotometry
narrower: GenevaPhotometry
narrower: StromgrenPhotometry
narrower: VilniusPhotometry
narrower: WalravenPhotometry
narrower: infraredPhotometry
narrower: ultravioletPhotometry
pref label: medium band photometry
related: broadBandPhotometry
related: narrowBandPhotometry

megalithicAstronomy
type: Concept
broader: archaeoastronomy
definition: megalithic astronomy
pref label: megalithic astronomy

megamaser
type: Concept
broader: maser
definition: megamaser
pref label: megamaser

meitnerium
type: Concept
alt label: Mt
broader: fundamentalChemicalElement
definition: meitnerium (atomic number 109)
history note: FVH: new (2007-OCT-25)
pref label: meitnerium

mendelevium
type: Concept
alt label: Md
broader: fundamentalChemicalElement
definition: mendelevium (atomic number 101)
history note: FVH: new (2007-OCT-25)
pref label: mendelevium

Mercury
type: Concept
broader: planet
definition: the planet Mercury
history note: FVH: new (2007-SEP-24)
pref label: Mercury
related: SolarSystem
scope note: See mercury for the element rather than the planet.

mercuryManganeseStar
type: Concept
broader: BStar
broader: magneticStar
definition: mercury manganese star
pref label: mercury manganese star
related: manganese
related: mercury

mercury
type: Concept
alt label: Hg
broader: fundamentalChemicalElement
definition: mercury (atomic number 80)
pref label: mercury
related: mercuryManganeseStar
scope note: Don't get confused with the planet Mercury (2007-NOV-13)

merger
type: Concept
definition: merger
narrower: galaxyMerger
pref label: merger

meridianCircle
type: Concept
broader: transitInstrument
definition: meridian circle
pref label: meridian circle
related: astrometry
related: meridian
related: quadrant
related: verticalCircle

meridian
type: Concept
definition: meridian
history note: FVH: new (2007-OCT-3)
pref label: meridian
related: celestialSphere
related: horizonCoordinateSystem
related: meridianCircle
related: meridianObservation

meridianObservation
type: Concept
definition: meridian observation
pref label: meridian observation
related: meridian
related: transitInstrument
related: transitTelescope
related: transitTime
related: zenithTelescope

meson
type: Concept
broader: boson
broader: elementaryParticle
definition: meson
pref label: meson
related: photon
related: quark

mesopause
type: Concept
definition: mesopause
pref label: mesopause
related: EarthAtmosphere
related: ionosphere
related: mesosphere
related: thermosphere

mesosphere
type: Concept
definition: mesosphere
pref label: mesosphere
related: EarthAtmosphere
related: mesopause
related: stratopause
related: upperAtmosphere

MeStar
type: Concept
broader: MStar
broader: emissionLineStar
definition: Me star
pref label: Me star
related: MeVariableStar
related: lateTypeVariableStar

metagalaxy
type: Concept
definition: metagalaxy
pref label: metagalaxy
related: universe

metalAbundance
type: Concept
alt label: metallicity
broader: abundance
definition: metal abundance
pref label: metal abundance
related: CnoAnomaly
related: OosterhoffGroup
related: chemicalElement
related: dredgeUp
related: heliumPoorStar
related: heliumRichStar
related: hydrogenDeficientStar
related: metalDeficientStar
related: metalPoorStar
related: metalRichStar
related: rareEarth
related: traceElement

metalDeficientStar
type: Concept
broader: star
definition: metal-deficient star
pref label: metal-deficient star
related: metalAbundance
related: metalPoorStar
related: ultravioletExcessStar

metalLine
type: Concept
broader: spectralLine
definition: metal line
narrower: CaIiEmissionLine
narrower: calciumLine
narrower: carbonLine
narrower: technetiumLine
pref label: metal line
related: absorptionLine
related: lineBlanketing
related: rareEarth

metalPoorStar
type: Concept
alt label: metal poor star
broader: star
change note: FVH: added NT POP II and III STARS (2007-SEP-21)
definition: metal-poor star
narrower: lithiumPoorStar
narrower: populationIiStar
narrower: populationIiiStar
narrower: weakGBandStar
pref label: metal-poor star
related: metalAbundance
related: metalDeficientStar
related: ultravioletExcessStar

metalRichStar
type: Concept
alt label: metallic line star
broader: star
definition: metal rich star
narrower: AmStar
narrower: siliconStar
pref label: metal-rich star
related: metalAbundance
related: redGiantBump

meteorCamera
type: Concept
definition: meteor camera
narrower: BakerNunnCamera
pref label: meteor camera

meteoriteCrater
type: Concept
definition: meteorite crater
pref label: meteorite crater
related: meteor
related: meteorite
related: meteoriteImpact

meteoriteImpact
type: Concept
definition: meteorite impact
pref label: meteorite impact
related: meteor
related: meteorite
related: meteoriteCrater

meteorite
type: Concept
broader: meteor
definition: meteorite
narrower: achondrite
narrower: aerolite
narrower: ataxite
narrower: australite
narrower: bediasite
narrower: chondrite
narrower: ironMeteorite
narrower: micrometeorite
narrower: moldavite
narrower: tektite
pref label: meteorite
related: NeumannLine
related: ablation
related: asteroid
related: collision
related: comet
related: impactCrater
related: interplanetaryMatter
related: meteoriteCrater
related: meteoriteImpact

meteor
type: Concept
definition: meteor
narrower: bolide
narrower: fireball
narrower: meteorite
pref label: meteor
related: crater
related: meteorShower
related: meteorStream
related: meteorTrail
related: meteoriteCrater
related: meteoriteImpact
related: meteoroid
related: meteoroidDustCloud
related: radiantMeteor

meteoroidDustCloud
type: Concept
definition: meteoroid dust cloud
pref label: meteoroid dust cloud
related: asteroid
related: comet
related: meteor
related: meteoroid
related: zodiacalDust

meteoroid
type: Concept
alt label: meteorids
broader: interplanetaryDust
broader: interplanetaryGrain
broader: interplanetaryMatter
definition: meteoroid
narrower: micrometeoroid
pref label: meteoroid
related: asteroid
related: comet
related: meteor
related: meteoroidDustCloud
related: zodiacalDust

meteorology
type: Concept
definition: meteorology
pref label: meteorology
related: EarthAtmosphere

meteorShower
type: Concept
definition: meteor shower
pref label: meteor shower
related: meteor
related: meteorStream
related: meteorTrail
related: radiantMeteor
related: zenithHourlyRate
scope note: named shower not included

meteorStream
type: Concept
definition: meteor stream
pref label: meteor stream
related: asteroid
related: comet
related: meteor
related: meteorShower
related: meteorTrail
related: radiantMeteor

meteorTrail
type: Concept
definition: meteor trail
pref label: meteor trail
related: meteor
related: meteorShower
related: meteorStream
related: radiantMeteor

methane
type: Concept
alt label: CH4
alt label: CH_4
broader: interstellarMolecule
broader: molecule
definition: methane molecule
history note: FVH: new (2007-OCT-5)
pref label: methane
related: molecularCloud

metonicCycle
type: Concept
definition: metonic cycle
pref label: metonic cycle
related: SarosCycle
related: lunarPhase

metrology
type: Concept
definition: metrology
pref label: metrology
related: instrument
related: measurement
related: unit

MeVariableStar
type: Concept
broader: MGiant
broader: emissionLineStar
broader: lateTypeVariableStar
definition: Me variable star
pref label: Me variable star
related: MeStar

MGiant
type: Concept
broader: MStar
broader: giant
broader: lateTypeGiant
definition: M giant star
narrower: MeVariableStar
pref label: M giant
related: MSubgiant

MichelsonInterferometer
type: Concept
broader: opticalInterferometer
definition: Michelson interferometer
pref label: Michelson interferometer
related: MichelsonInterferometry
related: intensityInterferometer

MichelsonInterferometry
type: Concept
definition: Michelson interferometry
pref label: Michelson interferometry
related: MichelsonInterferometer
related: opticalInterferometry

microchannelPlate
type: Concept
broader: amplifier
definition: micro-channel plate
history note: FVH: new (2007-SEP-21)
pref label: microchannel plate
related: imageTube

microdensitometer
type: Concept
broader: measuringInstrument
definition: microdensitometer
pref label: microdensitometer
related: densitometer
related: microphotometer
related: photograph

microdensitometry
type: Concept
definition: microdensitometry
pref label: microdensitometry
scope note: see microdensitometer

micrometeorite
type: Concept
broader: meteorite
definition: micrometeorite
pref label: micrometeorite
related: interplanetaryMatter

micrometeoroid
type: Concept
broader: meteoroid
definition: micrometeoroid
pref label: micrometeoroid

micrometer
type: Concept
broader: measuringInstrument
definition: micrometer
pref label: micrometer

microphotometer
type: Concept
broader: measuringInstrument
definition: microphotometer
pref label: microphotometer
related: microdensitometer
related: photography

microprocessor
type: Concept
broader: computer
definition: microprocessor
pref label: microprocessor
related: controlSystem

microturbulence
type: Concept
broader: turbulenceEarthAtmosphere
broader: turbulenceStarAtmosphere
definition: microturbulence
pref label: microturbulence
related: absorptionLine
related: atmosphere

microwaveAntenna
type: Concept
alt label: microwave antennas
broader: antenna
definition: microwave antennaa
pref label: microwave antenna
related: microwaveRadiation

microwaveBackground
type: Concept
broader: backgroundRadiation
broader: cosmicNoise
broader: microwaveRadiation
change note: FVH: Added RT COSMOLOGY (2007-SEP-21)
definition: cosmic microwave background
pref label: microwave background
related: SunyaevZeldovichEffect
related: XRayBackground
related: cosmology
related: gammaRayBackground
related: radioBackground
related: ultravioletBackground

microwaveEmission
type: Concept
broader: emissionSpectrum
definition: microwave emission
pref label: microwave emission
related: cosmicNoise

microwaveImaging
type: Concept
definition: microwave imaging
pref label: microwave imaging
related: microwaveRadiation

microwave
type: Concept
definition: microwave
pref label: microwave
related: millimeterRadiation
scope note: combine with other terms

microwaveRadiation
type: Concept
broader: electromagneticRadiation
definition: microwave radiation
narrower: microwaveBackground
pref label: microwave radiation
related: microwaveAntenna
related: microwaveImaging
related: millimeterRadiation
related: remoteSensing

microwaveSpectroscopy
type: Concept
broader: spectroscopy
definition: microwave spectroscopy
pref label: microwave spectroscopy

microwaveSpectrum
type: Concept
broader: spectrum
definition: microwave spectrum
pref label: microwave spectrum
related: radioSpectrum

MieScattering
type: Concept
broader: scattering
definition: Mie scattering
pref label: Mie scattering
related: RayleighScattering
related: brillouinScattering

MilkyWayGalaxy
type: Concept
alt label: the Galaxy
broader: LocalGroup
broader: galaxy
broader: spiralGalaxy
definition: the Milky Way galaxy
pref label: Milky Way galaxy
related: GalacticAnticenter
related: GalacticBulge
related: GalacticCenter
related: GalacticCluster
related: GalacticCoordinateSystem
related: GalacticCosmicRay
related: GalacticEquator
related: GalacticHalo
related: GalacticLatitude
related: GalacticLongitude
related: GalacticPlane
related: GalacticPole
related: GalacticRotation
related: GouldsBelt
related: highVelocityCloud
related: highVelocityStar
related: skyBrightness

millimeterAstronomy
type: Concept
broader: radioAstronomy
definition: millimeter astronomy
pref label: millimeter astronomy
related: radioObservatory
related: satelliteBorneInstrument
related: submillimeterAstronomy

millimeterRadiation
type: Concept
alt label: millimeter wave
alt label: mm radiation
broader: electromagneticRadiation
change note: FVH: added BT electromagnetic_radiation (2007-OCT-8)
definition: millimeter radiation
pref label: millimeter radiation
related: microwave
related: microwaveRadiation

MillsCrossAntenna
type: Concept
alt label: Mills cross antennas
broader: antenna
broader: directionalAntenna
broader: radioTelescope
definition: Mills cross antenna
pref label: Mills cross antenna
related: pencilBeam

MilneEddingtonApproximation
type: Concept
definition: Milne Eddington approximation
pref label: Milne Eddington approximation
related: lineWidth
related: spectroscopicAnalysis

mineralDeposit
type: Concept
definition: mineral deposit
pref label: mineral deposit
related: mineralogy

mineralogy
type: Concept
definition: mineralogy
pref label: mineralogy
related: mineralDeposit

minimum
type: Concept
broader: photometricElement
definition: minimum
pref label: minimum
related: lightCurve
related: maximum
related: variableStar
related: velocityCurve

minorAxis
type: Concept
broader: semiminorAxis
definition: minor axis
history note: ES: new (2007-OCT-11)
history note: see terms under major axis
pref label: minor axis
related: axialRatio
related: majorAxis

minorPlanetFamily
type: Concept
definition: minor planet family
narrower: AmorGroup
narrower: ApolloGroup
narrower: HirayamaFamily
narrower: TrojanGroup
pref label: minor planet family
related: asteroid
scope note: not a complete list of terms

MiraVariableStar
type: Concept
alt label: Miras
alt label: omicron Ceti star
alt label: zeta Aurigae star
broader: emissionLineStar
broader: irregularVariableStar
broader: lateTypeGiant
broader: longPeriodVariableStar
broader: pulsatingVariableStar
definition: Mira variable star
pref label: Mira variable star
related: SVulpeculaeStar
related: radialPulsation
related: semiRegularVariableStar

mirrorCell
type: Concept
definition: mirror cell
pref label: mirror cell
related: mirror

mirror
type: Concept
broader: opticalComponent
definition: mirror
narrower: dichroicMirror
narrower: primaryMirror
narrower: telescopeMirror
pref label: mirror
related: aluminizing
related: aluminumCoating
related: catadioptricSystem
related: catoptricSystem
related: coating
related: collimator
related: figuring
related: glass
related: mirrorCell
related: opticalAberration
related: opticalInstrument
related: opticalMaterial
related: opticalSurface
related: polishing
related: reflection
related: thinFilm

missingMass
type: Concept
definition: missing mass
pref label: missing mass
related: cosmology
related: galaxyCluster
related: massToLightRatio
related: velocityDispersion

MkClassification
type: Concept
broader: spectralClassification
definition: MK classification
narrower: luminosityClass
pref label: MK classification
related: luminosity
related: spectrum

MMagnitude
type: Concept
broader: apparentMagnitude
definition: M magnitude
pref label: M magnitude
related: farInfraredRadiation
related: infraredPhotometry

model
type: Concept
definition: model
narrower: computerModel
narrower: orrery
pref label: model
related: equilibriumFigures
related: numericalSimulation
related: polytrope
related: simulation
related: stellarStructure
scope note: combine with other terms

ModifiedNewtonianDynamics
type: Concept
alt label: MOND
broader: gravitation
definition: MOdified Newtonian Dynamics
pref label: MOdified Newtonian Dynamics
related: NewtonianGravitation
related: gravitationalEffect
related: gravitationalForce

modulation
type: Concept
definition: modulation
pref label: modulation
scope note: combine with other terms

modulationTransferFunction
type: Concept
alt label: MTF
broader: transferFunction
definition: modulation transfer function
pref label: modulation transfer function
related: opticalInstrument
related: opticalTesting
related: opticalTransferFunction

moldavite
type: Concept
broader: meteorite
broader: tektite
definition: moldavite
pref label: moldavite
related: australite
related: bediasite
related: chondrite

molecularAstrophysics
type: Concept
definition: molecular astrophysics
pref label: molecular astrophysics
related: cosmochemistry
related: molecularBand
related: molecularLine
related: molecularSpectroscopy

molecularBand
type: Concept
broader: spectralBand
definition: molecular band
narrower: BBand
narrower: GBand
narrower: PhillipsBand
narrower: SwanBand
pref label: molecular band
related: lateTypeStar
related: molecularAstrophysics
related: molecularLine
related: molecularSpectrum
related: zirconiumStar

molecularCloud
type: Concept
broader: interstellarMatter
definition: molecular cloud
narrower: giantMolecularCloud
pref label: molecular cloud
related: interstellarMolecule
related: methane
related: molecularHydrogen

molecularHydrogen
type: Concept
broader: hydrogen
broader: interstellarMolecule
broader: molecule
definition: molecular hydrogen
narrower: orthohydrogen
narrower: parahydrogen
pref label: molecular hydrogen
related: molecularCloud

molecularLine
type: Concept
broader: spectralLine
definition: molecular line
pref label: molecular line
related: fineStructure
related: lateTypeStar
related: molecularAstrophysics
related: molecularBand
related: spectralBand

molecularSpectroscopy
type: Concept
definition: molecular spectroscopy
pref label: molecular spectroscopy
related: molecularAstrophysics
scope note: see molecular spectrum

molecularSpectrum
type: Concept
broader: spectrum
definition: molecular spectrum
narrower: PhillipsBand
narrower: pBranch
pref label: molecular spectrum
related: BBand
related: GBand
related: RamanSpectroscopy
related: SwanBand
related: lateTypeStar
related: molecularBand
related: molecule
related: organicMolecule
related: qBranch
related: spectralBand
related: vibrationalSpectrum

molecule
type: Concept
broader: matter
definition: molecule
narrower: hydratedCarbon
narrower: interstellarMolecule
narrower: methane
narrower: molecularHydrogen
narrower: organicMolecule
pref label: molecule
related: molecularSpectrum

molybdenum
type: Concept
alt label: Mo
broader: fundamentalChemicalElement
definition: molybdenum (atomic number 42)
history note: FVH: new (2007-OCT-25)
pref label: molybdenum

momentum
type: Concept
definition: momentum
pref label: momentum
related: angularMomentum
related: mass
related: velocity

monochromator
type: Concept
broader: measuringInstrument
broader: opticalInstrument
definition: monochromator
pref label: monochromator

MonteCarloTechnique
type: Concept
broader: dataProcessing
definition: Monte Carlo technique
pref label: Monte Carlo technique
related: statistics

Moon
type: Concept
broader: satellite
definition: Moon
pref label: Moon
related: Earthshine
related: anomalisticMonth
related: apogee
related: crater
related: crust
related: crustalDynamics
related: equationOfTheCenter
related: libration
related: lunarDome
related: lunarEclipse
related: lunarLaserRanging
related: lunarOccultation
related: lunarTheory
related: mantle
related: maria
related: mascon
related: moonquake
related: nutation
related: occultation
related: perigee
related: phaseAngle
related: phaseDefect
related: ray
related: regressionOfNode
related: selenology
related: solarEclipse
related: surfaceOfCelestialBody
scope note: Earth's satellite; see under satellite or planet for more rts; see also lunar

moonquake
type: Concept
definition: moonquake
pref label: moonquake
related: Moon
related: earthquake

morphology
type: Concept
definition: morphology
pref label: morphology
related: classification
related: diskFlaring
scope note: combine with other terms

motion
type: Concept
definition: motion
narrower: apparentSuperluminalMotion
narrower: apsidalMotion
narrower: internalMotion
narrower: orbitalMotion
narrower: polarMotion
narrower: properMotion
narrower: solarMotion
narrower: spaceMotion
narrower: stellarMotion
narrower: waveMotion
pref label: motion
related: orbit
related: orrery
related: planetarium
scope note: combine with other terms

mottle
type: Concept
definition: mottle
pref label: mottle
related: Sun
related: chromosphere

movingClusterParallax
type: Concept
alt label: cluster parallax
broader: parallax
definition: moving cluster parallax
pref label: moving cluster parallax
related: dynamicalParallax
related: kinematicParallax
related: openStarCluster
related: properMotion
related: radiantMovingCluster
related: secularParallax

mRegion
type: Concept
broader: solarCorona
definition: m region
pref label: m region

MStar
type: Concept
broader: lateTypeStar
definition: M star
narrower: MDwarf
narrower: MGiant
narrower: MSubdwarf
narrower: MSubgiant
narrower: MSupergiant
narrower: MeStar
pref label: M star
related: spectralType
related: titaniumOxide

MSubdwarf
type: Concept
broader: MStar
broader: subdwarf
definition: M subdwarf star
pref label: M subdwarf

MSubgiant
type: Concept
broader: MStar
broader: subgiant
definition: M subgiant star
pref label: M subgiant
related: MGiant

MSupergiant
type: Concept
broader: MStar
broader: lateTypeSupergiant
definition: M supergiant star
pref label: M supergiant

multiChannelDetector
type: Concept
alt label: multichannel detector
broader: detector
definition: multi-channel detector
narrower: CcdDetector
narrower: diodeArray
narrower: imageTube
narrower: reticonArray
narrower: televisionDetector
pref label: multi-channel detector
related: chargeCoupledDevice
related: multiChannelSpectrograph

multiChannelSpectrograph
type: Concept
alt label: multi-channel spectrometer
alt label: multichannel spectrograph
broader: spectrograph
definition: multi-channel spectrograph
pref label: multi-channel spectrograph
related: multiChannelDetector

multiColorPhotometry
type: Concept
alt label: multicolor photometry
broader: photometry
definition: multi-color photometry
pref label: multi-color photometry

multiFiberSpectrograph
type: Concept
broader: spectrograph
definition: multi-fiber spectrograph
history note: FVH: new (2007-SEP-21)
pref label: multi-fiber spectrograph
related: integralFieldSpectrograph
related: opticalFiber
related: threeDimensionalSpectrum

multiPeriodicPulsation
type: Concept
alt label: multiperiodic pulsation
definition: multi-periodic pulsation
narrower: doubleModePulsation
pref label: multi-periodic pulsation
related: FourierAnalysis
related: frequencyAnalysis
related: multiPeriodicVariableStar
related: pulsatingVariableStar
related: pulsationMode

multiPeriodicVariableStar
type: Concept
alt label: multiperiodic variable star
broader: periodicVariableStar
broader: pulsatingVariableStar
definition: multi-periodic variable star
narrower: Pg1159Star
narrower: RsCanumVenaticorumStar
narrower: SxPhoenicisStar
narrower: ZzCetiStar
narrower: betaCepheiStar
narrower: deltaScutiStar
narrower: doubleModeVariableStar
narrower: dwarfCepheid
pref label: multi-periodic variable star
related: multiPeriodicPulsation
related: overtoneFrequency
related: overtoneMode
related: pulsationMode

multipleGalaxy
type: Concept
broader: galaxy
definition: multiple galaxy
pref label: multiple galaxy
related: galaxyCluster
related: galaxyGroup

multipleMirrorTelescope
type: Concept
alt label: MMT
broader: opticalTelescope
broader: reflectingTelescope
definition: multiple mirror telescope
pref label: multiple mirror telescope
related: activeOptics
related: segmentedOptics
related: veryLargeTelescope

multipleStar
type: Concept
change note: FVH: moved triple_star to NT (2007-OCT-1)
definition: multiple star
narrower: tripleStar
pref label: multiple star
related: binaryStar
related: companionStar
related: orbit
related: orbitDetermination

multiSlitSpectrograph
type: Concept
broader: spectrograph
definition: multi-slit spectrograph
history note: FVH: new (2007-SEP-21)
pref label: multi-slit spectrograph
related: integralFieldSpectrograph
related: spectrographSlit
related: threeDimensionalSpectrum

muon
type: Concept
broader: lepton
definition: muon
pref label: muon

nadir
type: Concept
broader: pole
definition: nadir
pref label: nadir
related: horizonCoordinateSystem
related: zenith

nakedSingularity
type: Concept
broader: singularity
definition: naked singularity
pref label: naked singularity
related: blackHole
related: quantumCosmology
related: spaceTimeSingularity
related: whiteHole

narrowBandPhotometry
type: Concept
broader: CcdPhotometry
broader: photoelectricPhotometry
definition: narrow-band photometry
narrower: HAlphaPhotometry
narrower: HBetaPhotometry
pref label: narrow band photometry
related: broadBandPhotometry
related: mediumBandPhotometry

NasmythFocus
type: Concept
broader: focus
definition: Nasmyth focus
pref label: Nasmyth focus
related: CassegrainFocus
related: CoudeFocus
related: NewtonianFocus
related: primeFocus
related: tertiaryMirror

naturalLineBroadening
type: Concept
broader: lineBroadening
definition: natural line broadening
pref label: natural line broadening
related: naturalLineWidth
related: spectralLine

naturalLineWidth
type: Concept
broader: lineWidth
definition: natural line width
pref label: natural line width
related: DopplerBroadening
related: StarkBroadening
related: ZeemanSplitting
related: lineBroadening
related: naturalLineBroadening
related: pressureBroadening
related: spectralLine

nauticalAlmanac
type: Concept
broader: almanac
definition: nautical almanac
pref label: nautical almanac
related: ephemeris

NavarroFrenkWhiteProfile
type: Concept
alt label: NFW
alt label: NFW profile
alt label: NFW-profile
broader: massDistribution
definition: Navarro-Frenk-White mass-profile
history note: FVH: new (2007-OCT-5)
pref label: Navarro-Frenk-White profile
related: BurkertProfile
related: exponentialProfile
related: isothermalSphere

NBodyProblem
type: Concept
alt label: N body problem
alt label: many body problem
alt label: many-body problem
definition: N-body problem
pref label: N-body problem
related: NBodySimulation
related: celestialMechanics
related: orbit
related: perturbation
related: stellarDynamics
related: threeBodyProblem
related: twoBodyProblem

NBodySimulation
type: Concept
broader: numericalSimulation
definition: N-body simulation
history note: FVH: new (2007-OCT-3)
pref label: N-body simulation
related: NBodyProblem

nearbyDwarf
type: Concept
broader: dwarf
broader: nearbyStar
definition: nearby dwarf star
pref label: nearby dwarf

nearbyGalaxy
type: Concept
broader: galaxy
definition: nearby galaxy
narrower: LocalGroup
narrower: MagellanicCloud
pref label: nearby galaxy
related: brightGalaxy

nearbyStar
type: Concept
definition: nearby star
narrower: nearbyDwarf
pref label: nearby star
related: trigonometricParallax

nearEarthAsteroid
type: Concept
alt label: NEO
alt label: near Earth asteroid
alt label: near-Earth object
broader: asteroid
definition: near-Earth asteroid
pref label: near-Earth asteroid

nearInfraredRadiation
type: Concept
broader: infraredRadiation
definition: near infrared radiation
pref label: near infrared radiation
related: HMagnitude
related: IMagnitude
related: JMagnitude
related: KMagnitude
related: LMagnitude
related: farInfraredRadiation
related: infraredPhotometry

nearUltravioletRadiation
type: Concept
alt label: NUV
broader: ultravioletRadiation
definition: near ultraviolet radiation
pref label: near ultraviolet radiation
related: extremeUltravioletRadiation
related: farUltravioletRadiation

nebula
type: Concept
broader: interstellarMatter
definition: nebula
narrower: bipolarNebula
narrower: brightNebula
narrower: compactNebula
narrower: darkNebula
narrower: denseCloud
narrower: diffuseNebula
narrower: dustNebula
narrower: emissionNebula
narrower: filamentaryNebula
narrower: gaseousNebula
narrower: planetaryNebula
narrower: reflectionNebula
narrower: ringNebula
pref label: nebula
related: OpikTheory
related: forbiddenLine
related: forbiddenTransition
related: nebularFilament
related: surfacePhotometry
scope note: named nebula not included; not including galaxy

nebularFilament
type: Concept
broader: interstellarMatter
definition: nebular filament
pref label: nebular filament
related: filamentaryNebula
related: nebula

negativeHIon
type: Concept
alt label: H minus ion
alt label: H-
alt label: H- ion
broader: hydrogen
definition: negative hydrogen ion
pref label: negative H ion
related: opacity
related: stellarAtmosphere

neighborhood
type: Concept
definition: neighborhood
pref label: neighborhood
scope note: combine with other terms

neodymium
type: Concept
alt label: Nd
broader: fundamentalChemicalElement
broader: rareEarth
definition: neodymium (atomic number 60)
history note: FVH: new (2007-OCT-25)
pref label: neodymium

neon
type: Concept
alt label: Ne
broader: fundamentalChemicalElement
definition: neon (atomic number 10)
history note: FVH: new (2007-OCT-25)
pref label: neon

Neptune
type: Concept
broader: JovianPlanet
broader: planet
definition: Neptune
history note: FVH: new (2007-SEP-24)
pref label: Neptune
related: SolarSystem

neptunium
type: Concept
alt label: Np
broader: fundamentalChemicalElement
definition: neptunium (atomic number 93)
history note: FVH: new (2007-OCT-25)
pref label: neptunium

NeumannLine
type: Concept
definition: Neumann line
pref label: Neumann line
related: emissionLine
related: emissionSpectrum
related: meteorite

neutralDensityFilter
type: Concept
broader: filter
definition: neutral density filter
history note: FVH: new (2007-SEP-21)
pref label: neutral density filter
related: attenuation

neutralGas
type: Concept
broader: gas
definition: neutral gas
narrower: HI
narrower: HeI
pref label: neutral gas
related: HIRegion

neutrino
type: Concept
broader: elementaryParticle
broader: lepton
broader: particle
definition: neutrino
pref label: neutrino
related: antineutrino
related: solarNeutrinoProblem
related: supernova

neutron
type: Concept
broader: elementaryParticle
broader: fundamentalParticle
definition: neutron
pref label: neutron
related: alphaParticle
related: nucleusAtom

neutronStar
type: Concept
broader: collapsedStar
broader: compactObject
broader: degenerateStar
broader: relativisticStar
broader: stellarObject
definition: neutron star
narrower: HzHerculisStar
narrower: magnetar
pref label: neutron star
related: AlfvenSurface
related: XRayBinaryStar
related: XRayBurst
related: XRayPulsar
related: lowMassXRayBinaryStar
related: pulsar
related: quark
related: relativisticAstrophysics
related: supernovaRemnant

NewtonianFocus
type: Concept
broader: NewtonianTelescope
broader: focus
definition: Newtonian focus
pref label: Newtonian focus
related: CassegrainFocus
related: CoudeFocus
related: NasmythFocus

NewtonianGravitation
type: Concept
broader: gravitation
definition: Newtonian gravitation
pref label: Newtonian gravitation
related: ModifiedNewtonianDynamics
related: generalTheoryOfRelativity
related: gravitationalConstant
related: gravitationalForce

NewtonianTelescope
type: Concept
definition: Newtonian telescope
narrower: NewtonianFocus
pref label: Newtonian telescope

NGalaxy
type: Concept
broader: compactGalaxy
broader: galaxy
definition: N galaxy
pref label: N galaxy
related: YerkesClassification
related: galacticNucleus
related: giantRadioGalaxy

nickel
type: Concept
alt label: Ni
broader: fundamentalChemicalElement
definition: nickel (atomic number 28)
history note: FVH: new (2007-OCT-25)
pref label: nickel

nightSkyBrightness
type: Concept
alt label: night sky background
broader: skyBrightness
definition: night sky brightness
pref label: night sky brightness
related: Rayleigh
related: RayleighScattering
related: airglow
related: aurora
related: gegenschein
related: zodiacalLight

nightVision
type: Concept
definition: night vision
pref label: night vision
related: darkAdaption

niobium
type: Concept
alt label: Nb
broader: fundamentalChemicalElement
definition: niobium (atomic number 41)
history note: FVH: new (2007-OCT-25)
pref label: niobium

nitrogen
type: Concept
alt label: N
broader: fundamentalChemicalElement
definition: nitrogen (atomic number 7)
history note: FVH: new (2007-OCT-25)
pref label: nitrogen
related: carbonNitrogenCycle

NMagnitude
type: Concept
broader: apparentMagnitude
definition: N magnitude
pref label: N magnitude
related: farInfraredRadiation
related: infraredPhotometry

nobelium
type: Concept
alt label: No
broader: fundamentalChemicalElement
definition: nobelium (atomic number 102)
history note: FVH: new (2007-OCT-25)
pref label: nobelium

noctilucentCloud
type: Concept
broader: cloud
definition: noctilucent cloud
pref label: noctilucent cloud
related: EarthAtmosphere
related: luminescence
scope note: in Earth's atmosphere

node
type: Concept
alt label: line of node
definition: node
narrower: ascendingNode
narrower: descendingNode
pref label: node
related: inclination
related: orbit
related: vibration

noise
type: Concept
change note: FVH: moved interference_noise to NT (2007-OCT-1)
definition: noise
narrower: backgroundNoise
narrower: cosmicNoise
narrower: interferenceNoise
narrower: readOutNoise
narrower: shotNoise
narrower: skyNoise
pref label: noise
related: integrationTime
related: signalToNoiseRatio
scope note: combine with other terms

nomenclature
type: Concept
definition: nomenclature
pref label: nomenclature
related: catalog
related: classification

nonEquilibriumFlow
type: Concept
alt label: nonequilibrium flow
broader: flow
definition: non-equilibrium flow
pref label: non-equilibrium flow
related: flowInstability

nonLteTransfer
type: Concept
alt label: nonLTE transfer
definition: non-LTE transfer
pref label: non-LTE transfer
related: energyTransfer
related: localThermodynamicEquilibrium
related: radiationMechanism

nonMainSequenceStar
type: Concept
alt label: nonmain_sequence star
definition: non-main_sequence star
narrower: evolvedStar
narrower: postMainSequenceStar
narrower: preMainSequenceStar
pref label: non-main sequence star
scope note: only the broad classes are shown below; specific type will be found under these, or from the hierarchical list

nonRadialPulsation
type: Concept
alt label: nonradial pulsation
definition: non-radial pulsation
pref label: non-radial pulsation
related: ZzCetiStar
related: betaCepheiStar
related: deltaScutiStar
related: pulsatingVariableStar
related: pulsationMode

nonThermalParticle
type: Concept
alt label: nonthermal particle
definition: non-thermal particle
pref label: non-thermal particle
related: nonThermalSource

nonThermalRadiation
type: Concept
alt label: nonthermal radiation
definition: non-thermal radiation
pref label: non-thermal radiation
related: nonThermalSource

nonThermalSource
type: Concept
alt label: nonthermal source
broader: source
definition: non-thermal source
pref label: non-thermal source
related: nonThermalParticle
related: nonThermalRadiation
related: synchrotronRadiation

NorthCelestialPole
type: Concept
alt label: N.C.P.
alt label: NCP
broader: celestialPole
definition: North Celestial Pole
pref label: North Celestial Pole
related: SouthCelestialPole

NorthEclipticPole
type: Concept
alt label: N.E.P.
alt label: NEP
broader: eclipticPole
definition: North Ecliptic Pole
pref label: North Ecliptic Pole
related: SouthEclipticPole

northernHemisphere
type: Concept
definition: northern hemisphere
pref label: northern hemisphere
related: southernHemisphere

NorthGalacticPole
type: Concept
alt label: N.G.P.
alt label: NGP
broader: GalacticPole
definition: North Galactic Pole
pref label: North Galactic Pole
related: SouthGalacticPole

novaLikeVariable
type: Concept
broader: cataclysmicVariableStar
definition: nova-like variable
narrower: AmCanumVenaticorumStar
narrower: UxUrsaeMajorisStar
narrower: VySculpturisStar
pref label: nova-like variable

nova
type: Concept
broader: eruptiveBinaryStar
broader: highLuminosityStar
definition: nova
narrower: XRayNova
narrower: classicalNova
narrower: fastNova
narrower: recurrentNova
narrower: slowNova
narrower: symbioticNova
pref label: nova
related: massLoss
related: opticalOutburst
related: preNova
related: progenitor
related: supernova

NStar
type: Concept
broader: lateTypeStar
definition: N star
pref label: N star
related: spectralType
related: technetiumStar

nuclearAstrophysics
type: Concept
definition: nuclear astrophysics
pref label: nuclear astrophysics
related: highEnergyAstrophysics
related: nuclearPhysics

nuclearFission
type: Concept
broader: fission
broader: nuclearReaction
definition: nuclear fission
pref label: nuclear fission
related: cosmochronology
related: radioactivity

nuclearFusion
type: Concept
broader: fusion
broader: nuclearReaction
definition: nuclear fusion
narrower: carbonBurning
narrower: heliumBurning
narrower: oxygenBurning
narrower: siliconBurning
pref label: nuclear fusion
related: carbonFlash
related: carbonNitrogenCycle
related: eProcess
related: heliumFlash
related: heliumShellFlash
related: hydrogenBurning
related: protonProtonReaction
related: shellBurning
related: stellarInterior
related: supernova

nuclearPhysics
type: Concept
definition: nuclear physics
pref label: nuclear physics
related: interaction
related: nuclearAstrophysics
related: nuclearRadiation
related: nuclearReaction
related: strongInteraction
related: weakInteraction

nuclearRadiation
type: Concept
definition: nuclear radiation
narrower: alphaParticle
narrower: electron
narrower: gammaRayRadiation
narrower: positron
pref label: nuclear radiation
related: CerenkovRadiation
related: nuclearPhysics

nuclearReaction
type: Concept
definition: nuclear reaction
narrower: nuclearFission
narrower: nuclearFusion
narrower: urcaProcess
pref label: nuclear reaction
related: carbonBurning
related: nuclearPhysics
related: nucleosynthesis
related: solarNeutrinoProblem

nucleosynthesis
type: Concept
definition: nucleosynthesis
narrower: carbonBurning
narrower: heliumBurning
narrower: hydrogenBurning
narrower: oxygenBurning
narrower: siliconBurning
pref label: nucleosynthesis
related: nuclearReaction
related: pProcess
related: rProcess
related: sProcess
related: stellarInterior
related: supernova

nucleusAtom
type: Concept
definition: nucleus [atom]
narrower: BoseEinsteinNucleus
narrower: FermiDiracNucleus
pref label: nucleus atom
related: neutron
related: proton

nucleusCelestialObject
type: Concept
definition: nucleus [celestial object]
narrower: compactNucleus
narrower: galacticNucleus
pref label: nucleus celestial object
related: cDGalaxy
related: comet
related: dirtySnowballTheory
scope note: combine with other terms

numericalAnalysis
type: Concept
broader: dataProcessing
definition: numerical analysis
pref label: numerical analysis
related: numericalIntegration
related: numericalMethod
related: numericalSimulation

numericalIntegration
type: Concept
definition: numerical integration
pref label: numerical integration
related: numericalAnalysis
related: numericalMethod

numericalMethod
type: Concept
definition: numerical method
pref label: numerical method
related: numericalAnalysis
related: numericalIntegration
related: numericalSimulation

numericalSimulation
type: Concept
definition: numerical simulation
narrower: NBodySimulation
narrower: SphSimulation
pref label: numerical simulation
related: computerModel
related: model
related: numericalAnalysis
related: numericalMethod

nutation
type: Concept
definition: nutation
pref label: nutation
related: EarthRotation
related: Moon
related: equationOfTheEquinox
related: polarMotion
related: precession

OAssociation
type: Concept
alt label: O-association
broader: starAssociation
definition: O association
pref label: O association
related: OCluster
related: ObAssociation

ObAssociation
type: Concept
broader: starAssociation
definition: OB association
pref label: OB association
related: OAssociation
related: youngStar

objectiveGrating
type: Concept
broader: diffractionGrating
broader: transmissionGrating
definition: objective grating
pref label: objective grating
related: echelleGrating
related: reflectionGrating

objective
type: Concept
definition: objective [optics]
narrower: primaryLens
narrower: primaryMirror
pref label: objective
related: opticalTelescope
scope note: primary optics of telescope

objectivePrism
type: Concept
broader: prism
definition: objective prism
pref label: objective prism
related: SchmidtTelescope

oblateness
type: Concept
definition: oblateness
pref label: oblateness
related: ellipticalGalaxy
related: equatorialBulge
related: planet
related: rotation

obliqueRotator
type: Concept
definition: oblique rotator
pref label: oblique rotator
related: ApStar
related: magneticStar
related: spectrumVariableStar

obliquityOfEcliptic
type: Concept
alt label: obliquity
definition: obliquity of ecliptic
pref label: obliquity of ecliptic
related: celestialEquator
related: ecliptic
related: eclipticPlane
related: phaseDefect
related: precession

observationalCosmology
type: Concept
definition: observational cosmology
pref label: observational cosmology
related: HubbleLaw
related: colorRedshiftRelation
related: cosmologicalDistanceScale
related: galaxyCount
related: galaxyDistribution
related: observation
related: radioSourceCount
related: redshift
related: redshiftDistanceRelation

observation
type: Concept
definition: observation
narrower: CcdObservation
narrower: opticalObservation
pref label: observation
related: dataAcquisition
related: observationalCosmology
related: observingTechnique
related: research
scope note: combine with other terms

observatory
type: Concept
definition: observatory
narrower: XRayObservatory
narrower: antarcticObservatory
narrower: gammaRayObservatory
narrower: geophysicalObservatory
narrower: infraredObservatory
narrower: opticalObservatory
narrower: radioObservatory
narrower: spaceObservatory
narrower: ultravioletObservatory
pref label: observatory
related: dome
related: planetarium
related: siteProtection
related: siteTesting
related: telescope
scope note: only the broad classes are shown below; specific type will be found under these, or from the hierarchical list

observingTechnique
type: Concept
alt label: method of observation
definition: observing technique
narrower: astrometry
narrower: interferometry
narrower: photometry
narrower: polarimetry
narrower: radioAstrometry
narrower: radioInterferometry
narrower: spectrophotometry
narrower: spectroscopy
pref label: observing technique
related: astronomicalTechnique
related: dataAcquisition
related: dataProcessing
related: observation
related: occultation
related: photography
scope note: only the broad classes are shown below; specific type will be found under these, or from the hierarchical list

ObStar
type: Concept
broader: earlyTypeStar
broader: youngStar
definition: OB star
narrower: BStar
narrower: OStar
narrower: ObSupergiant
pref label: OB star
related: runawayStar
related: youngStarCluster

ObSupergiant
type: Concept
broader: ObStar
broader: earlyTypeSupergiant
definition: OB supergiant star
narrower: BSupergiant
narrower: OSupergiant
pref label: OB supergiant

occultation
type: Concept
change note: FVH: added asteroid_occultation and lunar_occultation (2007-OCT-8)
definition: occultation
narrower: asteroidOccultation
narrower: lunarOccultation
narrower: radioOccultation
pref label: occultation
related: Moon
related: angularDiameter
related: binaryStar
related: diameter
related: eclipse
related: observingTechnique
related: planet
related: transit

occultingDisk
type: Concept
definition: occulting disc UK
definition: occulting disk
pref label: occulting disk
related: separation
related: visualBinaryStar

oceanography
type: Concept
definition: oceanography
pref label: oceanography
related: oceanTide

oceanTide
type: Concept
broader: tide
definition: ocean tide
pref label: ocean tide
related: oceanography

OCluster
type: Concept
broader: openStarCluster
definition: O-star cluster
pref label: O cluster
related: BStar
related: OAssociation
related: OStar

ODwarf
type: Concept
broader: OStar
broader: dwarf
definition: O dwarf star
pref label: O dwarf

OefStar
type: Concept
broader: OStar
broader: earlyTypeEmissionStar
definition: Oef star
pref label: Oef star
related: OfStar

OeStar
type: Concept
broader: OStar
broader: earlyTypeEmissionStar
definition: Oe star
pref label: Oe star

OfStar
type: Concept
broader: OStar
broader: earlyTypeEmissionStar
definition: Of star
pref label: Of star
related: OefStar

OGiant
type: Concept
broader: OStar
definition: O giant star
pref label: O giant

OhAbsorption
type: Concept
broader: interstellarAbsorption
definition: OH absorption
pref label: OH absorption
related: hydroxylRadical

OhCloud
type: Concept
broader: interstellarMatter
definition: OH cloud
pref label: OH cloud
related: hydroxylRadical

OhEmission
type: Concept
broader: emissionSpectrum
definition: OH emission
pref label: OH emission
related: hydroxylRadical

OhIrStar
type: Concept
alt label: OH-IR star
broader: OhSource
broader: giant
broader: infraredSource
definition: OH/IR star
pref label: OH IR star
related: OhMaser
related: hydroxylRadical
related: variableStar

OhLine
type: Concept
definition: OH line
pref label: OH line
related: hydroxylRadical

OhMaser
type: Concept
broader: maser
definition: OH maser
pref label: OH maser
related: OhIrStar
related: SiOMaser
related: hydroxylRadical
related: waterMaser
scope note: subtype not included

OhSource
type: Concept
broader: radioSource
definition: OH source
narrower: OhIrStar
pref label: OH source
related: hydroxylRadical

oldStar
type: Concept
broader: evolvedStar
change note: FVH: added NT POPULATION_III_STARS (2007-SEP-21)
definition: old star
narrower: populationIiStar
narrower: populationIiiStar
narrower: preGalacticStar
pref label: old star

OMagnitude
type: Concept
broader: apparentMagnitude
definition: O magnitude
pref label: O magnitude
related: farInfraredRadiation
related: infraredPhotometry

OmegaBaryon
type: Concept
alt label: Omega(baryon)
broader: OmegaParameter
definition: Omega(baryon), the cosmological baryon mass-density fraction
history note: FVH: new (2007-OCT-24)
pref label: Omega baryon
related: baryon
related: massDensity

OmegaLambda
type: Concept
alt label: Omega(Lambda)
broader: OmegaParameter
definition: Omega(Lambda), the cosmological vacuum energy density fraction
history note: FVH: new (2007-OCT-24)
pref label: Omega Lambda
related: cosmologicalConstant
related: energyDensity

OmegaMass
type: Concept
alt label: Omega(mass)
broader: OmegaParameter
definition: omega(mass), the cosmological matter density fraction
history note: FVH: new (2007-OCT-24)
pref label: Omega mass
related: massDensity

OmegaParameter
type: Concept
broader: cosmologicalParameter
definition: the cosmological density fraction parameter, Omega
history note: FVH: new (2007-SEP-21)
narrower: OmegaBaryon
narrower: OmegaLambda
narrower: OmegaMass
pref label: Omega parameter
related: cosmology
related: energyDensity
related: massDensity

onLineSystem
type: Concept
alt label: on line system
definition: on-line system
pref label: on-line system
related: dataCenter
related: dataProcessing

OortCloud
type: Concept
alt label: Oort comet cloud
definition: Oort cloud
pref label: Oort cloud
related: comet
related: transNeptunianObject

OortConstant
type: Concept
broader: astronomicalConstant
definition: Oort constant
pref label: Oort constant
related: GalacticRotation
related: GalacticStructure

OortFormulae
type: Concept
alt label: Oort formulas
definition: Oort formulae
pref label: Oort formulae
related: GalacticRotation
related: GalacticStructure

OosterhoffGroup
type: Concept
definition: Oosterhoff group
pref label: Oosterhoff group
related: RrLyraeStar
related: globularStarCluster
related: metalAbundance

opacity
type: Concept
broader: opticalProperty
definition: opacity
narrower: KramersOpacity
narrower: RosselandOpacity
pref label: opacity
related: absorption
related: atmosphere
related: negativeHIon
related: opticalDepth
related: radiation
related: radiativeTransfer
related: transparency

openStarCluster
type: Concept
broader: starCluster
definition: open star cluster
narrower: GalacticCluster
narrower: OCluster
narrower: youngStarCluster
pref label: open star cluster
related: blueStragglerStar
related: movingClusterParallax
related: populationIStar
related: radiantMovingCluster
related: spiralArm
related: starAssociation
related: turnoffPoint

openUniverse
type: Concept
broader: cosmology
definition: open universe
pref label: open universe
related: BigBangTheory
related: closedUniverse
related: steadyStateTheory

OpikTheory
type: Concept
definition: Opik theory
pref label: Opik theory
related: nebula
related: supernova

opposition
type: Concept
definition: opposition
pref label: opposition
related: conjunction
related: quadrature
related: synodicPeriod
related: syzygy
scope note: refers to planet position

opticalAberration
type: Concept
alt label: aberration
change note: FVH: renamed for more clarity (2007-OCT-3)
definition: aberration of optical image
narrower: astigmatism
narrower: chromaticAberration
narrower: comaticAberration
narrower: distortion
narrower: fieldCurvature
narrower: sphericalAberration
pref label: optical aberration
related: focus
related: lens
related: mirror
related: opticalSystem
related: optics
related: telescope

opticalBurst
type: Concept
broader: burst
definition: optical burst
pref label: optical burst
related: XRayBurst
related: burster
related: gammaRayBurst
related: radioBurst
scope note: specifically from burster

opticalComponent
type: Concept
definition: optical component
narrower: correctorPlate
narrower: diffractionGrating
narrower: fieldCorrector
narrower: grism
narrower: interferenceFilter
narrower: lens
narrower: mirror
narrower: opticalFiber
narrower: opticalFilter
narrower: opticalWaveguide
narrower: opticalWindow
pref label: optical component
scope note: not a complete list of terms

opticalDepth
type: Concept
alt label: optical thickness
definition: optical depth
pref label: optical depth
related: absorptionCoefficient
related: gasDensity
related: opacity

opticalDesign
type: Concept
definition: optical design
pref label: optical design
related: opticalInstrument

opticalDoubleStar
type: Concept
definition: apparent optical double star
pref label: optical double star
related: angularSeparation
scope note: use only for pair in chance alignment; refer also to visual binary star

opticalFiber
type: Concept
alt label: glass fiber
broader: opticalComponent
broader: opticalWaveguide
definition: optical fiber
pref label: optical fiber
related: fiberOptics
related: glass
related: multiFiberSpectrograph
related: opticalInstrument

opticalFilm
type: Concept
alt label: film [optical]
definition: optical film
narrower: antireflectionCoating
narrower: thinFilm
pref label: optical film
related: dichroicMirror
related: interferenceFilter
related: lightInterference

opticalFilter
type: Concept
alt label: color filter
broader: filter
broader: opticalComponent
definition: optical filter
narrower: interferenceFilter
narrower: iodineCell
narrower: photographicFilter
pref label: optical filter
related: dichroicMirror
related: lightInterference
related: opticalWindow
related: photometry
related: ultravioletFilter

opticalFlare
type: Concept
broader: flare
definition: optical flare
pref label: optical flare
related: flareStar
related: prominence

opticalGlass
type: Concept
broader: glass
broader: opticalMaterial
definition: optical glass
pref label: optical glass
related: opticalWindow

opticalIdentification
type: Concept
alt label: optical counterparts
definition: optical identification
pref label: optical identification
related: XRayIdentification
related: XRaySource
related: gammaRaySource
related: radioSource

opticalInstrument
type: Concept
alt label: optical equipment
definition: optical instrument
narrower: camera
narrower: coronagraph
narrower: monochromator
narrower: opticalScanners
narrower: photometer
narrower: polarimeter
narrower: seeingMonitor
narrower: spectrograph
narrower: telescope
pref label: optical instrument
related: HartmannTest
related: collimator
related: fieldCorrector
related: lens
related: mirror
related: modulationTransferFunction
related: opticalDesign
related: opticalFiber
related: opticalMaterial
related: opticalSystem
related: opticalTesting
related: opticalTransferFunction
related: prism
scope note: only the broad classes are shown below; specific type will be found under these, or from the hierarchical list

opticalInterferometer
type: Concept
alt label: stellar interferometer
broader: interferometer
definition: optical interferometer
narrower: MichelsonInterferometer
narrower: intensityInterferometer
pref label: optical interferometer
related: longBaselineInterferometer

opticalInterferometry
type: Concept
alt label: light interferometry
alt label: stellar interferometry
broader: interferometry
definition: optical interferometry
pref label: optical interferometry
related: MichelsonInterferometry
related: interferenceFringe
related: interferenceWave
related: lightInterference
related: longBaselineInterferometry

opticalMaterial
type: Concept
definition: optical material
narrower: glass
narrower: opticalGlass
pref label: optical material
related: lens
related: mirror
related: opticalInstrument

opticalObservation
type: Concept
broader: observation
definition: optical observation
pref label: optical observation
related: opticalObservatory

opticalObservatory
type: Concept
broader: observatory
definition: optical observatory
narrower: HubbleSpaceTelescope
pref label: optical observatory
related: opticalObservation
related: opticalTelescope
related: seeingMonitor

opticalOutburst
type: Concept
broader: outburst
definition: optical outburst
pref label: optical outburst
related: cataclysmicVariableStar
related: flareStar
related: nova
related: supernova
scope note: not from burster

opticalPathlength
type: Concept
definition: optical pathlength
pref label: optical pathlength
related: refractiveIndex

opticalPosition
type: Concept
definition: optical position
pref label: optical position
related: astrometry

opticalProperty
type: Concept
broader: property
definition: optical property
narrower: albedo
narrower: brightness
narrower: color
narrower: opacity
narrower: refractiveIndex
pref label: optical property
related: brightnessTemperature
related: darkness
related: isotropy
related: lightPolarization
related: optics
scope note: not a complete list of terms

opticalPulsar
type: Concept
broader: pulsar
definition: optical pulsar
pref label: optical pulsar
related: radioPulsar

opticalRadar
type: Concept
broader: radar
definition: optical radar
pref label: optical radar
related: laser
related: laserRanging
related: lunarLaserRanging
related: satelliteLaserRanging

opticalScanners
type: Concept
broader: opticalInstrument
definition: optical scanners
pref label: optical scanners
related: spectrophotometry

opticalSpectrograph
type: Concept
alt label: optical spectrometer
broader: spectrograph
definition: optical spectrograph
pref label: optical spectrograph

opticalSpectroscopy
type: Concept
broader: spectroscopy
definition: optical spectroscopy
pref label: optical spectroscopy

opticalSurface
type: Concept
change note: FVH: renamed from optical_surface (2007-OCT-2)
definition: optical surface
pref label: optical surface
related: aluminumCoating
related: antireflectionCoating
related: figuring
related: lens
related: mirror
related: polishing
related: silverCoating
related: thinFilm

opticalSystem
type: Concept
definition: optical system
narrower: catadioptricSystem
narrower: catoptricSystem
narrower: dioptricSystem
pref label: optical system
related: aperture
related: chromaticAberration
related: comaticAberration
related: distortion
related: fieldCurvature
related: opticalAberration
related: opticalInstrument

opticalTelescope
type: Concept
broader: telescope
definition: optical telescope
narrower: automaticPatrolTelescope
narrower: multipleMirrorTelescope
narrower: reflectingTelescope
narrower: refractingTelescope
narrower: veryLargeTelescope
pref label: optical telescope
related: catadioptricSystem
related: catoptricSystem
related: dioptricSystem
related: eyepiece
related: objective
related: opticalObservatory
related: secondaryMirror
related: tertiaryMirror

opticalTesting
type: Concept
definition: optical testing
pref label: optical testing
related: figuring
related: modulationTransferFunction
related: opticalInstrument
related: opticalTransferFunction

opticalTransferFunction
type: Concept
alt label: OTF
broader: transferFunction
definition: optical transfer function
pref label: optical transfer function
related: modulationTransferFunction
related: opticalInstrument
related: opticalTesting

opticalTransmissionWindow
type: Concept
broader: atmosphericWindow
change note: FVH: renamed to avoid confusion with optics (2007-NOV-2)
definition: optical transmission window through the atmosphere
pref label: optical transmission window
related: infraredTransmissionWindow
related: radioTransmissionWindow
scope note: low absorption in atmosphere

opticalWaveguide
type: Concept
broader: opticalComponent
broader: waveguide
definition: optical waveguide
narrower: opticalFiber
pref label: optical waveguide

opticalWindow
type: Concept
broader: opticalComponent
definition: optical window [optics]
pref label: optical window
related: opticalFilter
related: opticalGlass

optics
type: Concept
definition: optics
narrower: activeOptics
narrower: adaptiveOptics
narrower: astronomicalOptics
narrower: fiberOptics
pref label: optics
related: adjustment
related: angularResolution
related: collimation
related: opticalAberration
related: opticalProperty
related: refractiveIndex
related: resolution
related: transmission
scope note: combine with other terms

orbitalAnomaly
type: Concept
alt label: apparent anomaly
broader: orbitalElement
definition: orbital_anomaly
narrower: eccentricAnomaly
narrower: meanAnomaly
narrower: realAnomaly
narrower: trueAnomaly
pref label: orbital anomaly
related: anomalisticMonth
related: anomalisticYear

orbitalElement
type: Concept
change note: FVH: removed element_of_orbit (2007-SEP-24)
definition: orbital element
narrower: apsis
narrower: centerOfMass
narrower: eccentricity
narrower: inclination
narrower: orbitalAnomaly
narrower: osculatoryElement
narrower: period
narrower: positionAngle
narrower: semimajorAxis
pref label: orbital element
related: acceleration
related: celestialMechanics
related: orbit
related: regressionOfNode
scope note: see also orbit

orbitalEvolution
type: Concept
definition: orbital evolution
pref label: orbital evolution
related: celestialMechanics

orbitalMotion
type: Concept
broader: motion
definition: orbital motion
pref label: orbital motion
related: celestialMechanics
related: circularOrbit
related: orbitalVelocity
related: visualBinaryStar

orbitalTheory
type: Concept
definition: orbital theory
pref label: orbital theory
related: celestialMechanics

orbitalVelocity
type: Concept
broader: velocity
definition: orbital velocity
pref label: orbital velocity
related: angularVelocity
related: escapeVelocity
related: orbit
related: orbitalMotion
related: tangentialVelocity

orbitDetermination
type: Concept
definition: orbit determination
pref label: orbit determination
related: binaryStar
related: multipleStar
related: planet

orbit
type: Concept
definition: orbit
narrower: KeplerianOrbit
narrower: ellipticalOrbit
narrower: geocentricOrbit
narrower: heliocentricOrbit
narrower: hyperbolicOrbit
narrower: osculatingOrbit
narrower: parabolicOrbit
narrower: periodicOrbit
narrower: polarOrbit
pref label: orbit
related: LocalStandardOfRest
related: NBodyProblem
related: RocheLimit
related: SchwarzschildMetric
related: acceleration
related: apsidalMotion
related: apsis
related: binaryStar
related: celestialMechanics
related: highVelocityStar
related: motion
related: multipleStar
related: node
related: orbitalElement
related: orbitalVelocity
related: parabolicVelocity
related: period
related: perturbation
related: perturbationTheory
related: planet
related: positionAngle
related: synchronousRotation
related: threeBodyProblem
related: trajectory
scope note: see also orbital element

organicMatter
type: Concept
definition: organic matter
narrower: organicMolecule
pref label: organic matter

organicMolecule
type: Concept
broader: molecule
broader: organicMatter
definition: organic molecule
pref label: organic molecule
related: interstellarMolecule
related: molecularSpectrum

orientation
type: Concept
definition: orientation
pref label: orientation
related: adjustment
related: alignmentOptics
related: collimation
related: positionAngle

origin
type: Concept
definition: origin
pref label: origin
related: SolarSystem
related: chemicalElement
related: elementFormation
related: galaxy
related: life
related: planet
scope note: combine with other terms

orionPopulationStar
type: Concept
definition: orion population star
pref label: orion population star
related: earlyTypeStar
related: preMainSequenceStar

orrery
type: Concept
broader: model
definition: orrery
pref label: orrery
related: motion
related: planetarium

orthohydrogen
type: Concept
broader: molecularHydrogen
definition: orthohydrogen
pref label: orthohydrogen
related: parahydrogen

orthoscopicEyepiece
type: Concept
broader: eyepiece
definition: orthoscopic eyepiece
pref label: orthoscopic eyepiece

oscillatingUniverse
type: Concept
broader: cosmology
definition: oscillating universe
pref label: oscillating universe
related: FriedmannUniverse

oscillation
type: Concept
definition: oscillation
pref label: oscillation
related: amplitude
related: decayOscillation
related: eFoldingTime
related: pendulum
related: wave
scope note: combine with other terms

oscillatorStrength
type: Concept
alt label: f value
alt label: f-value
definition: oscillator strength
pref label: oscillator strength
related: gValue
related: gfValue
related: lineFormation
related: lineWidth
related: transitionProbability

osculatingOrbit
type: Concept
broader: orbit
definition: osculating orbit
pref label: osculating orbit

osculatoryElement
type: Concept
broader: orbitalElement
definition: osculatory element
pref label: osculatory element
related: celestialMechanics
related: perturbation

osmium
type: Concept
alt label: Os
broader: fundamentalChemicalElement
definition: osmium (atomic number 76)
history note: FVH: new (2007-OCT-25)
pref label: osmium

OStar
type: Concept
broader: ObStar
broader: earlyTypeStar
broader: youngStar
definition: O star
narrower: ODwarf
narrower: OGiant
narrower: OSubdwarf
narrower: OSupergiant
narrower: OeStar
narrower: OefStar
narrower: OfStar
pref label: O star
related: OCluster
related: WolfRayetStar
related: earlyTypeVariableStar
related: spectralType

OSubdwarf
type: Concept
broader: OStar
broader: subdwarf
definition: O subdwarf star
pref label: O subdwarf

OSupergiant
type: Concept
broader: OStar
broader: ObSupergiant
broader: earlyTypeSupergiant
broader: supergiant
definition: O supergiant star
pref label: O supergiant

outburst
type: Concept
broader: burst
broader: flare
definition: outburst
narrower: opticalOutburst
pref label: outburst
related: highState
related: lowState

outerPlanet
type: Concept
broader: planet
definition: outer planet
narrower: JovianPlanet
pref label: outer planet
related: innerPlanet

outgassing
type: Concept
definition: outgassing
pref label: outgassing
related: cryogenics
related: vacuumTechnique

overabundance
type: Concept
broader: abundance
definition: overabundance
history note: ES: new (2007-OCT-8)
pref label: overabundance
related: underabundance

overtoneFrequency
type: Concept
alt label: harmonic overtones
alt label: overtones
definition: overtone frequency
pref label: overtone frequency
related: FourierAnalysis
related: fundamentalFrequency
related: harmonicFrequency
related: multiPeriodicVariableStar
related: overtoneMode
scope note: see sn for overtone mode; also see harmonic frequency

overtoneMode
type: Concept
alt label: overtones
broader: pulsationMode
definition: overtone mode
pref label: overtone mode
related: fundamentalMode
related: multiPeriodicVariableStar
related: overtoneFrequency
related: pulsatingVariableStar
scope note: of pulsation frequency, not Fourier component of non-sinusoidal variation

oxygenBurning
type: Concept
broader: nuclearFusion
broader: nucleosynthesis
definition: oxygen burning
pref label: oxygen burning
related: carbonBurning
related: heliumBurning
related: hydrogenBurning
related: oxygen
related: stellarInterior

oxygen
type: Concept
alt label: O
broader: fundamentalChemicalElement
definition: oxygen (atomic number 8)
history note: FVH: new (2007-OCT-25)
pref label: oxygen
related: oxygenBurning
related: titaniumOxide

ozoneLayer
type: Concept
definition: ozone layer
pref label: ozone layer
related: EarthAtmosphere

pairAnnihilation
type: Concept
definition: pair annihilation
pref label: pair annihilation
related: electron
related: gammaRayRadiation
related: positron

pairProduction
type: Concept
broader: particleProduction
definition: pair production
pref label: pair production
related: electron
related: gammaRayRadiation
related: positron

paleomagnetism
type: Concept
definition: paleomagnetism
pref label: paleomagnetism
related: continentalDrift
related: geomagnetism
related: magneticField

palladium
type: Concept
alt label: Pd
broader: fundamentalChemicalElement
definition: palladium (atomic number 46)
history note: FVH: new (2007-OCT-25)
pref label: palladium

parabolicAntenna
type: Concept
alt label: parabolic antennas
broader: antenna
broader: directionalAntenna
definition: parabolic antenna
pref label: parabolic antenna
related: CassegrainFocus

parabolicMirror
type: Concept
definition: parabolic mirror
pref label: parabolic mirror
related: parabolicReflector
scope note: see parabolic reflector

parabolicOrbit
type: Concept
broader: orbit
definition: parabolic orbit
pref label: parabolic orbit
related: circularOrbit
related: comet
related: ellipticalOrbit
related: hyperbolicOrbit

parabolicReflector
type: Concept
definition: parabolic reflector
pref label: parabolic reflector
related: dishAntenna
related: parabolicMirror
related: radarTelescope
related: radioTelescope
related: reflectingTelescope

parabolicVelocity
type: Concept
broader: velocity
definition: parabolic velocity
pref label: parabolic velocity
related: escapeVelocity
related: orbit

parahydrogen
type: Concept
broader: molecularHydrogen
definition: parahydrogen
pref label: parahydrogen
related: orthohydrogen

parallax
type: Concept
definition: parallax
narrower: annualParallax
narrower: diurnalParallax
narrower: dynamicalParallax
narrower: kinematicParallax
narrower: movingClusterParallax
narrower: photometricParallax
narrower: secularParallax
narrower: statisticalParallax
narrower: trigonometricParallax
pref label: parallax
related: AstronomicalUnit
related: astrometry
related: distance
related: distanceModulus

parallelComputer
type: Concept
broader: computer
definition: parallel computer
history note: FVH: new (2007-SEP-21)
pref label: parallel computer

parametricAmplifier
type: Concept
broader: amplifier
definition: parametric amplifier
pref label: parametric amplifier

parsec
type: Concept
alt label: parallax second
definition: parsec
pref label: parsec
related: AstronomicalUnit
related: distance
related: distanceScale
related: lightYear

partialEclipse
type: Concept
broader: eclipse
definition: partial eclipse
pref label: partial eclipse
related: eclipsingBinaryStar
related: totalEclipse

particleAcceleration
type: Concept
definition: particle acceleration
pref label: particle acceleration
related: elementaryParticle

particleAccretion
type: Concept
definition: particle accretion
pref label: particle accretion
related: accretion

particleBeam
type: Concept
definition: particle beam
pref label: particle beam
related: highEnergyAstrophysics

particleCreation
type: Concept
definition: particle creation
pref label: particle creation
related: elementaryParticle

particleEscape
type: Concept
definition: particle escape
pref label: particle escape
related: elementaryParticle

particleInteraction
type: Concept
definition: particle interaction
pref label: particle interaction
related: elementaryParticle

particle
type: Concept
definition: particle
narrower: alphaParticle
narrower: boson
narrower: electron
narrower: elementaryParticle
narrower: fundamentalParticle
narrower: ion
narrower: lepton
narrower: neutrino
narrower: plasma
narrower: positron
narrower: proton
narrower: relativisticParticle
pref label: particle
scope note: only the broad classes are shown below; specific type will be found under these, or from the hierarchical list

particleProduction
type: Concept
definition: particle production
narrower: pairProduction
pref label: particle production
related: elementaryParticle

particlePropagation
type: Concept
definition: particle propagation
pref label: particle propagation

PaschenBackEffect
type: Concept
definition: Paschen-Back effect
pref label: Paschen-Back effect
related: ZeemanSplitting
related: magneticField

PaschenSeries
type: Concept
alt label: Paschen line
broader: hydrogenSpectrum
definition: Paschen series
pref label: Paschen series
related: BalmerSeries
related: BrackettSeries
related: LymanSeries
related: PfundSeries

pastLightCone
type: Concept
broader: lightCone
definition: past light cone
pref label: past light cone
related: futureLightCone

PaulTrap
type: Concept
definition: Paul trap
pref label: Paul trap
related: electricField
related: ion
related: radioFrequency

pBranch
type: Concept
broader: molecularSpectrum
definition: p-branch
pref label: p branch

PCygniLineProfile
type: Concept
broader: lineProfile
definition: P Cygni line profile
pref label: P Cygni line profile
related: SDoradusStar
related: emissionLineStar
related: massLoss
related: shellStar
related: symbioticStar

peculiarGalaxy
type: Concept
broader: galaxy
broader: peculiarObject
definition: peculiar galaxy
narrower: EpGalaxy
narrower: SeyfertGalaxy
narrower: compactGalaxy
narrower: dwarfGalaxy
narrower: emissionLineGalaxy
narrower: interactingGalaxy
narrower: ringGalaxy
pref label: peculiar galaxy
related: MarkarianGalaxy

peculiarGiant
type: Concept
broader: giant
broader: peculiarStar
definition: peculiar giant star
pref label: peculiar giant

peculiarMotion
type: Concept
definition: peculiar motion
pref label: peculiar motion
related: LocalStandardOfRest
related: peculiarVelocity
related: properMotion
related: radialVelocity
related: stellarMotion

peculiarObject
type: Concept
definition: peculiar object
narrower: peculiarGalaxy
narrower: peculiarStar
pref label: peculiar object
scope note: combine with other terms

peculiarStar
type: Concept
broader: peculiarObject
definition: peculiar star
narrower: ApStar
narrower: BpStar
narrower: heavyMetalStar
narrower: holmiumStar
narrower: magneticStar
narrower: peculiarGiant
narrower: peculiarVariableStar
pref label: peculiar star
related: abnormalSpectrum
related: abundance
related: chemicalComposition
related: emissionLineStar
scope note: only the broad classes are shown below; specific type will be found under these, or from the hierarchical list

peculiarVariableStar
type: Concept
broader: peculiarStar
broader: variableStar
definition: peculiar variable star
pref label: peculiar variable star

peculiarVelocity
type: Concept
broader: velocity
definition: peculiar velocity
pref label: peculiar velocity
related: LocalStandardOfRest
related: peculiarMotion
related: radialVelocity
related: stellarMotion

pencilBeam
type: Concept
definition: pencil beam
pref label: pencil beam
related: MillsCrossAntenna
related: radioInterferometer

pendulum
type: Concept
broader: timingEquipment
definition: pendulum
pref label: pendulum
related: geodesy
related: gravity
related: oscillation

PenroseProcess
type: Concept
definition: Penrose process
pref label: Penrose process
related: blackHole

penumbralFilament
type: Concept
definition: penumbral filament
pref label: penumbral filament
related: penumbra

penumbra
type: Concept
alt label: penumbras
definition: penumbra
pref label: penumbra
related: WilsonEffect
related: eclipse
related: lunarEclipse
related: penumbralFilament
related: solarEclipse
related: sunspot
related: umbra

periapsis
type: Concept
definition: periapsis
pref label: periapsis
related: periastron
related: perihelion

periastron
type: Concept
broader: apsis
definition: periastron
pref label: periastron
related: apastron
related: periapsis

pericenter
type: Concept
definition: pericenter
pref label: pericenter
related: centerOfMass

perigee
type: Concept
broader: apsis
definition: perigee
pref label: perigee
related: Earth
related: Moon
related: apogee

perihelion
type: Concept
broader: apsis
definition: perihelion
pref label: perihelion
related: EarthOrbit
related: aphelion
related: periapsis
related: planet

periodAgeRelation
type: Concept
alt label: period age relation
broader: statisticalRelation
definition: period-age relation
pref label: period-age relation
related: Cepheid
related: periodColorRelation
related: periodDensityRelation
related: periodLuminosityColorRelation
related: periodLuminosityRelation
related: periodMassRelation
related: periodRadiusRelation
related: periodSpectrumRelation

periodChange
type: Concept
alt label: period variation
definition: period change
pref label: period change
related: binaryStar
related: pulsatingVariableStar

periodColorRelation
type: Concept
alt label: period color relation
broader: statisticalRelation
definition: period-color relation
pref label: period-color relation
related: Cepheid
related: periodAgeRelation
related: periodDensityRelation
related: periodLuminosityColorRelation
related: periodLuminosityRelation
related: periodMassRelation
related: periodRadiusRelation
related: periodSpectrumRelation
related: pulsatingVariableStar
related: radiusLuminosityRelation

periodDensityRelation
type: Concept
alt label: period density relation
broader: statisticalRelation
definition: period-density relation
pref label: period-density relation
related: periodAgeRelation
related: periodColorRelation
related: periodLuminosityColorRelation
related: periodLuminosityRelation
related: periodMassRelation
related: periodRadiusRelation
related: periodSpectrumRelation
related: pulsatingVariableStar
related: radiusLuminosityRelation

periodDetermination
type: Concept
definition: period determination
pref label: period determination
related: binaryStar
related: variableStar
related: waveformAnalysis

periodicComet
type: Concept
broader: comet
definition: periodic comet
pref label: periodic comet

periodicOrbit
type: Concept
broader: orbit
definition: periodic orbit
narrower: ellipticalOrbit
pref label: periodic orbit

periodicVariableStar
type: Concept
broader: pulsatingVariableStar
broader: rotatingStar
definition: periodic variable star
history note: FVH: new (2007-OCT-8)
narrower: multiPeriodicVariableStar
pref label: periodic variable star

periodLuminosityColorRelation
type: Concept
alt label: PLC relation
alt label: period luminosity color relation
broader: statisticalRelation
definition: period-luminosity-color relation
pref label: period-luminosity-color relation
related: Cepheid
related: periodAgeRelation
related: periodColorRelation
related: periodDensityRelation
related: periodLuminosityRelation
related: periodMassRelation
related: periodRadiusRelation
related: periodSpectrumRelation
related: pulsatingVariableStar
related: radiusLuminosityRelation

periodLuminosityRelation
type: Concept
alt label: PL relation
alt label: period luminosity relation
broader: statisticalRelation
definition: period-luminosity relation
pref label: period-luminosity relation
related: Cepheid
related: periodAgeRelation
related: periodColorRelation
related: periodDensityRelation
related: periodLuminosityColorRelation
related: periodMassRelation
related: periodRadiusRelation
related: periodSpectrumRelation
related: pulsatingVariableStar
related: radiusLuminosityRelation

periodMassRelation
type: Concept
alt label: period mass relation
broader: statisticalRelation
definition: period-mass relation
pref label: period-mass relation
related: periodAgeRelation
related: periodColorRelation
related: periodDensityRelation
related: periodLuminosityColorRelation
related: periodLuminosityRelation
related: periodRadiusRelation
related: periodSpectrumRelation
related: pulsatingVariableStar
related: radiusLuminosityRelation

period
type: Concept
broader: orbitalElement
broader: photometricElement
definition: period
pref label: period
related: binaryStar
related: cycle
related: lightCurve
related: orbit
related: phaseWave
related: planet
related: pulsatingVariableStar
related: pulsationMode
related: rotation
related: variableStar
related: velocityCurve

periodRadiusRelation
type: Concept
alt label: period radius relation
broader: statisticalRelation
definition: period-radius relation
pref label: period-radius relation
related: Cepheid
related: periodAgeRelation
related: periodColorRelation
related: periodDensityRelation
related: periodLuminosityColorRelation
related: periodLuminosityRelation
related: periodMassRelation
related: periodSpectrumRelation
related: pulsatingVariableStar
related: radiusLuminosityRelation

periodSpectrumRelation
type: Concept
alt label: period spectrum relation
broader: statisticalRelation
definition: period-spectrum relation
pref label: period-spectrum relation
related: Cepheid
related: periodAgeRelation
related: periodColorRelation
related: periodDensityRelation
related: periodLuminosityColorRelation
related: periodLuminosityRelation
related: periodMassRelation
related: periodRadiusRelation
related: pulsatingVariableStar
related: radiusLuminosityRelation

peripheral
type: Concept
definition: peripheral
pref label: peripheral
related: computer
related: instrument
scope note: combine with other terms

perturbation
type: Concept
definition: perturbation
pref label: perturbation
related: NBodyProblem
related: celestialMechanics
related: orbit
related: osculatoryElement
related: perturbationTheory
related: threeBodyProblem

perturbationTheory
type: Concept
definition: perturbation theory
pref label: perturbation theory
related: celestialMechanics
related: gravitation
related: orbit
related: perturbation

petrology
type: Concept
broader: geology
definition: petrology
pref label: petrology
related: planet
related: surfaceOfCelestialBody

PfundSeries
type: Concept
broader: hydrogenSpectrum
broader: infraredRadiation
definition: Pfund series
pref label: Pfund series
related: BalmerSeries
related: BrackettSeries
related: LymanSeries
related: PaschenSeries

Pg1159Star
type: Concept
alt label: GW Virginis star
alt label: PG1159-35 star
broader: DoStar
broader: multiPeriodicVariableStar
definition: PG1159 star
history note: ES: new (2007-OCT-8)
pref label: PG1159 star

phaseAngle
type: Concept
definition: phase angle
pref label: phase angle
related: Moon
related: lunarPhase
related: planet

phasedArray
type: Concept
broader: array
definition: phased array
pref label: phased array
related: phaseWave
related: radioInterferometer

phaseDefect
type: Concept
definition: phase defect
pref label: phase defect
related: Moon
related: lunarPhase
related: obliquityOfEcliptic

phaseDifference
type: Concept
definition: phase difference
pref label: phase difference
related: phaseWave

phaseEffect
type: Concept
definition: phase effect
pref label: phase effect
related: lunarPhase

phaseError
type: Concept
definition: phase error
pref label: phase error
related: phaseWave

phaseFunction
type: Concept
definition: phase function
pref label: phase function
related: phaseWave
related: radiationScattering

phaseRotator
type: Concept
definition: phase rotator
pref label: phase rotator
related: phaseWave
related: radioTelescope

phaseSensitiveDetector
type: Concept
definition: phase sensitive detector
pref label: phase sensitive detector
related: phaseSwitchingInterferometer
related: phaseWave
related: receiver

phaseShift
type: Concept
alt label: phase-shift
definition: phase shift
pref label: phase shift
related: lightCurve
related: phaseWave
related: variableStar
related: velocityCurve

phaseSpace
type: Concept
definition: phase space
pref label: phase space
related: phaseWave
related: velocitySpace

phaseSwitchingInterferometer
type: Concept
broader: interferometer
definition: phase switching interferometer
pref label: phase switching interferometer
related: phaseSensitiveDetector
related: phaseWave

phaseSwitching
type: Concept
definition: phase switching
pref label: phase switching
related: phaseWave
related: radioTelescope
related: receiver

phaseWave
type: Concept
definition: phase of a repeating wave
pref label: phase wave
related: binaryStar
related: lightCurve
related: period
related: phaseDifference
related: phaseError
related: phaseFunction
related: phaseRotator
related: phaseSensitiveDetector
related: phaseShift
related: phaseSpace
related: phaseSwitching
related: phaseSwitchingInterferometer
related: phasedArray
related: variableStar
related: velocityCurve

PhillipsBand
type: Concept
broader: infraredRadiation
broader: molecularBand
broader: molecularSpectrum
definition: Phillips band
pref label: Phillips band

phosphorescence
type: Concept
definition: phosphorescence
pref label: phosphorescence
related: imageTube
related: phosphorescentScintillation
related: phosphorus
related: scintillationCounter

phosphorescentScintillation
type: Concept
broader: scintillation
definition: phosphorescent scintillation
pref label: phosphorescent scintillation
related: cosmicRayShower
related: imageTube
related: phosphorescence
related: scintillationCounter

phosphorus
type: Concept
alt label: P
broader: fundamentalChemicalElement
definition: phosphorus (atomic number 15)
history note: FVH: new (2007-OCT-25)
pref label: phosphorus
related: phosphorescence

photocathode
type: Concept
broader: cathode
broader: electrode
definition: photocathode
pref label: photocathode
related: imageTube
related: photomultiplierTube

photochemistry
type: Concept
definition: photochemistry
pref label: photochemistry
related: photographicDeveloper
related: photographicMaterial
related: photographicProcessing

photoconductiveCell
type: Concept
definition: photoconductive cell
pref label: photoconductive cell
related: photomultiplierTube

photodiode
type: Concept
broader: photoelectronicDevice
definition: photodiode
narrower: avalanchePhotodiode
pref label: photodiode
related: photometry

photodissociation
type: Concept
definition: photodissociation
pref label: photodissociation
related: absorption

photoelectricInstrument
type: Concept
definition: photoelectric instrument
narrower: imageTube
narrower: photomultiplierTube
pref label: photoelectric instrument

photoelectricMagnitude
type: Concept
broader: apparentMagnitude
definition: photoelectric magnitude
pref label: photoelectric magnitude
related: photographicMagnitude
related: photovisualMagnitude

photoelectricPhotometer
type: Concept
broader: photometer
definition: photoelectric photometer
pref label: photoelectric photometer

photoelectricPhotometry
type: Concept
broader: photometry
definition: photoelectric photometry
narrower: broadBandPhotometry
narrower: mediumBandPhotometry
narrower: narrowBandPhotometry
pref label: photoelectric photometry
related: CcdPhotometry
related: photographicPhotometry

photoelectronicDevice
type: Concept
definition: photoelectronic device
narrower: avalanchePhotodiode
narrower: chargeCoupledDevice
narrower: chargeInjectionDevice
narrower: chargeTransferDevice
narrower: imageTube
narrower: photodiode
narrower: photomultiplierTube
narrower: televisionDetector
pref label: photoelectronic device

photogrammetry
type: Concept
definition: photogrammetry
pref label: photogrammetry
related: map
related: photograph
related: photography

photographicAstrometry
type: Concept
broader: astrometry
definition: photographic astrometry
pref label: photographic astrometry
related: properMotion

photographicDeveloper
type: Concept
definition: photographic developer
pref label: photographic developer
related: photochemistry
related: photograph
related: photographicProcessing

photographicEmulsion
type: Concept
broader: detector
broader: photographicMaterial
definition: photographic emulsion
pref label: photographic emulsion
related: halation
related: photograph
related: photographicFilm
related: photographicPlate
related: photography
related: quantumEfficiency
related: turbidity

photographicFilm
type: Concept
alt label: film [photographic]
broader: photographicMaterial
definition: photographic film
pref label: photographic film
related: photograph
related: photographicEmulsion
related: photography

photographicFilter
type: Concept
broader: opticalFilter
definition: photographic filter
pref label: photographic filter

photographicInstrument
type: Concept
definition: photographic instrument
narrower: SchmidtCamera
narrower: SchmidtTelescope
narrower: camera
pref label: photographic instrument

photographicMagnitude
type: Concept
broader: apparentMagnitude
definition: photographic magnitude
pref label: photographic magnitude
related: photoelectricMagnitude
related: photovisualMagnitude

photographicMaterial
type: Concept
definition: photographic material
narrower: photographicEmulsion
narrower: photographicFilm
narrower: photographicPlate
pref label: photographic material
related: photochemistry
related: photograph

photographicPhotometry
type: Concept
broader: photometry
definition: photographic photometry
narrower: broadBandPhotometry
pref label: photographic photometry
related: CcdPhotometry
related: photoelectricPhotometry

photographicPlate
type: Concept
broader: photographicMaterial
definition: photographic plate
pref label: photographic plate
related: photograph
related: photographicEmulsion
related: photography
related: reseaux

photographicProcessing
type: Concept
definition: photographic processing
pref label: photographic processing
related: darkroom
related: photochemistry
related: photographicDeveloper
related: photography
related: unsharpMasking

photograph
type: Concept
broader: image
definition: photograph
pref label: photograph
related: camera
related: microdensitometer
related: photogrammetry
related: photographicDeveloper
related: photographicEmulsion
related: photographicFilm
related: photographicMaterial
related: photographicPlate

photography
type: Concept
alt label: astrophotography
definition: photography
narrower: allSkyPhotography
narrower: colorPhotography
narrower: falseColorPhotography
narrower: spectrography
narrower: streakPhotography
narrower: ultravioletPhotography
pref label: photography
related: HdCurve
related: astronomicalTechnique
related: camera
related: darkroom
related: edgeEffect
related: image
related: microphotometer
related: observingTechnique
related: photogrammetry
related: photographicEmulsion
related: photographicFilm
related: photographicPlate
related: photographicProcessing
related: unsharpMasking

photoheliograph
type: Concept
definition: photoheliograph
pref label: photoheliograph
related: spectroheliograph

photoionization
type: Concept
alt label: photoionisation UK
broader: ionization
definition: photoionization
pref label: photoionization
related: absorption
related: aurora
related: electron
related: recombination

photoluminescence
type: Concept
broader: lightEmission
definition: photoluminescence
narrower: XRayFluorescence
pref label: photoluminescence
related: fluorescence

photometer
type: Concept
broader: opticalInstrument
broader: telescopeInstrument
definition: photometer
narrower: highSpeedPhotometer
narrower: photoelectricPhotometer
narrower: spectrophotometer
pref label: photometer
related: CcdDetector
related: bolometer
related: infraredDetector
related: photometry
related: photomultiplierTube
related: polarimeter
related: radiometer
related: ultravioletDetector

photometricElement
type: Concept
definition: photometric element
narrower: lightCurve
narrower: maximum
narrower: minimum
narrower: period
pref label: photometric element
related: eclipsingBinaryStar

photometricParallax
type: Concept
broader: parallax
definition: photometric parallax
pref label: photometric parallax
related: photometry

photometricStandardStar
type: Concept
broader: standardStar
definition: photometric standard star
pref label: photometric standard star
related: photometry
related: standardCandle

photometricSystem
type: Concept
definition: photometric system
narrower: BesselPhotometry
narrower: CapePhotometry
narrower: DdoPhotometry
narrower: GenevaPhotometry
narrower: GunnPhotometry
narrower: HstPhotometry
narrower: JohnsonPhotometry
narrower: KronCousinsPhotometry
narrower: SloanPhotometry
narrower: StromgrenPhotometry
narrower: WalravenPhotometry
narrower: rgbPhotometry
pref label: photometric system
related: apparentMagnitude
related: photometry

photometry
type: Concept
alt label: filter photometry
broader: astronomicalTechnique
broader: observingTechnique
definition: photometry
narrower: CcdPhotometry
narrower: infraredPhotometry
narrower: multiColorPhotometry
narrower: photoelectricPhotometry
narrower: photographicPhotometry
narrower: surfacePhotometry
narrower: ultravioletPhotometry
pref label: photometry
related: PurkinjeEffect
related: apparentMagnitude
related: automaticPatrolTelescope
related: avalanchePhotodiode
related: color
related: colorEquation
related: colorExcess
related: colorIndex
related: colorLuminosityRelation
related: colorMagnitudeRelation
related: driftScan
related: eRegion
related: effectiveTemperature
related: fRegion
related: interferenceFilter
related: intrinsicColor
related: magnitude
related: opticalFilter
related: photodiode
related: photometer
related: photometricParallax
related: photometricStandardStar
related: photometricSystem
related: polarimetry
related: spectrophotometry
related: standardCandle
related: twoColorDiagram
scope note: only the broad classes are shown below; specific type will be found under these, or from the hierarchical list

photomultiplierTube
type: Concept
alt label: photocell
alt label: photoelectric cell
broader: detector
broader: photoelectricInstrument
broader: photoelectronicDevice
definition: photomultiplier tube
pref label: photomultiplier tube
related: amplifier
related: cathode
related: electrode
related: photocathode
related: photoconductiveCell
related: photometer
related: quadrantDetector
related: quantumEfficiency
related: scintillationCounter

photonCountingSystem
type: Concept
definition: photon counting system
pref label: photon counting system
related: counter

photon
type: Concept
broader: boson
broader: elementaryParticle
definition: photon
pref label: photon
related: electromagneticRadiation
related: inverseComptonEffect
related: inverseComptonScattering
related: meson
related: quanta
related: radiation
related: radiationPressure
related: radiationScattering
related: radiativeRecombination

photosphere
type: Concept
alt label: reversing layer
definition: photosphere
pref label: photosphere
related: Sun
related: chromosphere
related: continuumRadiation
related: facula
related: granulation
related: granule
related: solarSurface
related: surfaceBrightness
related: surfaceOfCelestialBody
scope note: ALT reversing_layer seems old-fashioned (IAU)!

photovisualMagnitude
type: Concept
broader: apparentMagnitude
definition: photovisual magnitude
pref label: photovisual magnitude
related: VMagnitude
related: photoelectricMagnitude
related: photographicMagnitude
related: visualMagnitude

photovoltaicCell
type: Concept
broader: semiconductorDevice
definition: photovoltaic cell
pref label: photovoltaic cell

physicalConstant
type: Concept
alt label: fundamental constant
broader: constant
change note: FVH: renamed (see constant) (2007-OCT-11)
definition: physical constant
narrower: PlanckConstant
narrower: gravitationalConstant
narrower: velocityOfLight
pref label: physical constant
related: astronomicalConstant

pion
type: Concept
broader: boson
broader: elementaryParticle
definition: pion
pref label: pion

pitchAngle
type: Concept
definition: pitch angle
pref label: pitch angle
related: GalacticStructure
related: galaxyStructure
related: spiralArm
related: spiralGalaxy

pixel
type: Concept
alt label: picture element
alt label: voxel
definition: pixel
pref label: pixel
related: detector
related: resolution
related: twoDimensionalDetector

plage
type: Concept
definition: flocculi
definition: plage
definition: solar plage
pref label: plage
related: chromosphere
related: facula
related: sunspot

PlanckBlackBodyFormula
type: Concept
definition: Planck black body formula
pref label: Planck black body formula
related: PlanckConstant
related: electromagneticRadiation
related: radiation

PlanckConstant
type: Concept
broader: physicalConstant
definition: Planck's constant h
pref label: Planck constant
related: PlanckBlackBodyFormula

planePolarization
type: Concept
alt label: linear polarization
alt label: plane polarisation UK
broader: lightPolarization
change note: FVH: added ALT linear polarization (2007-SEP-21)
definition: plane polarization
pref label: plane polarization
related: circularPolarization
related: halfWavePlate

planetarium
type: Concept
definition: planetarium
pref label: planetarium
related: motion
related: observatory
related: orrery

planetar
type: Concept
broader: stellarObject
definition: planetar
history note: FVH: new (2007-OCT-12)
pref label: planetar
related: brownDwarf
related: planet

planetaryAlignment
type: Concept
definition: alignment of planet, etc.
pref label: planetary alignment
related: SolarSystem
related: celestialMechanics
related: planet

planetaryMicrolensing
type: Concept
broader: gravitationalMicrolensing
definition: microlensing of exoplanet
history note: FVH: new (2007-OCT-8)
pref label: planetary microlensing
related: planet

planetaryNebula
type: Concept
broader: emissionNebula
broader: evolvedStar
broader: nebula
definition: planetary nebula
pref label: planetary nebula
related: HarmanSeatonSequence
related: ansa
related: centralStar
related: emissionLineStar
related: excitingStar
related: massLoss
related: ringNebula

planetary
type: Concept
definition: planetary
pref label: planetary
scope note: see sn for planet

planetaryRing
type: Concept
broader: ring
definition: planetary ring
pref label: planetary ring
related: RocheLimit
related: planet
related: resonanceGap
related: ringDivision
related: shepherdSatellite

planetarySystem
type: Concept
definition: planetary system
narrower: SolarSystem
pref label: planetary system

planetaryTheory
type: Concept
definition: planetary theory
pref label: planetary theory
related: SolarSystem
related: celestialMechanics

planetesimal
type: Concept
definition: planetesimal
pref label: planetesimal
related: SolarSystem
related: asteroid
related: planet
related: protoplanet
related: satellite

planetology
type: Concept
definition: planetology
pref label: planetology
related: geology

planet
type: Concept
broader: rotatingBody
change note: FVH: added lots of planet, RT DWARF_PLANETS (2007-SEP-24)
definition: planet
narrower: Earth
narrower: Jupiter
narrower: Mars
narrower: Mercury
narrower: Neptune
narrower: Saturn
narrower: Uranus
narrower: Venus
narrower: extrasolarPlanet
narrower: giantPlanet
narrower: hypotheticalPlanet
narrower: innerPlanet
narrower: outerPlanet
pref label: planet
related: BodesLaw
related: RocheLimit
related: SolarSystem
related: aeronomy
related: aphelion
related: astrology
related: atmosphere
related: boundaryLayer
related: centerOfMass
related: collision
related: composition
related: core
related: crater
related: crust
related: dustStorm
related: dwarfPlanet
related: equatorialBulge
related: evolution
related: exosphere
related: galileanSatellite
related: geology
related: geomagnetism
related: greenhouseEffect
related: interior
related: lithosphere
related: mantle
related: map
related: meanEquinox
related: oblateness
related: occultation
related: orbit
related: orbitDetermination
related: origin
related: perihelion
related: period
related: petrology
related: phaseAngle
related: planetar
related: planetaryAlignment
related: planetaryMicrolensing
related: planetaryRing
related: planetesimal
related: polarCap
related: polarRegion
related: protoplanet
related: resonanceGap
related: rill
related: ringDivision
related: satellite
related: semimajorAxis
related: solarNebula
related: solarPlanetaryRelation
related: spaceExploration
related: structure
related: surfaceOfCelestialBody
related: synodicPeriod
related: syzygy
related: topography
related: twoBodyProblem
related: volatile
related: volcano
related: waterIce

planetSatellite
type: Concept
broader: satellite
definition: planet satellite
pref label: planet satellite

plasmaCloud
type: Concept
broader: cloud
definition: plasma cloud
pref label: plasma cloud
related: ion
related: plasma
related: plasmaJet

plasmaJet
type: Concept
broader: jet
definition: plasma jet
pref label: plasma jet
related: ion
related: plasma
related: plasmaCloud
related: plasmaLoop

plasmaLoop
type: Concept
definition: plasma loop
pref label: plasma loop
related: plasma
related: plasmaJet

plasmapause
type: Concept
definition: plasmapause
pref label: plasmapause
related: plasma

plasmaPhysics
type: Concept
definition: plasma physics
pref label: plasma physics
related: magnetohydrodynamics
related: plasma

plasma
type: Concept
alt label: cosmic plasma
broader: particle
definition: plasma
narrower: collisionalPlasma
narrower: lowTemperaturePlasma
narrower: relativisticPlasma
narrower: solarWind
narrower: stellarWind
pref label: plasma
related: HIiRegion
related: HoltsmarkApproximation
related: elementaryParticle
related: energeticParticle
related: ion
related: ionizedGas
related: plasmaCloud
related: plasmaJet
related: plasmaLoop
related: plasmaPhysics
related: plasmaWave
related: plasmapause
related: radiationBelt
related: radiativeRecombination
related: thermodynamics
related: viscosity

plasmaWave
type: Concept
definition: plasma wave
pref label: plasma wave
related: ionPlasmaWave
related: magnetohydrodynamics
related: plasma

platinum
type: Concept
alt label: Pt
broader: fundamentalChemicalElement
definition: platinum (atomic number 78)
history note: FVH: new (2007-OCT-25)
pref label: platinum

Pluto
type: Concept
broader: dwarfPlanet
definition: Pluto
history note: FVH: new (2007-OCT-2)
pref label: Pluto
related: SolarSystem

plutonium
type: Concept
alt label: Pu
broader: fundamentalChemicalElement
definition: plutonium (atomic number 94)
history note: FVH: new (2007-OCT-25)
pref label: plutonium

PMagnitude
type: Concept
broader: apparentMagnitude
definition: P magnitude
pref label: P magnitude
related: farInfraredRadiation
related: infraredPhotometry

PogsonScale
type: Concept
definition: Pogson scale
pref label: Pogson scale
related: magnitude

PoincareTheorem
type: Concept
definition: Poincare theorem
pref label: Poincare theorem
related: starCluster
related: stellarDynamics

pointingAccuracy
type: Concept
definition: pointing accuracy
pref label: pointing accuracy
related: controlSystem
related: pointingError
related: telescope
related: tracking

pointingError
type: Concept
definition: pointing error
pref label: pointing error
related: controlSystem
related: pointingAccuracy
related: telescope
related: tracking

pointSpreadFunction
type: Concept
alt label: PSF
broader: transferFunction
definition: point spread function
pref label: point spread function
related: atmosphericRefraction
related: seeing
related: turbulenceEarthAtmosphere

polarAxis
type: Concept
definition: polar axis
pref label: polar axis
related: celestialPole
related: telescopeMounting

polarCap
type: Concept
definition: polar cap
pref label: polar cap
related: Earth
related: planet

polarDiagram
type: Concept
definition: polar diagram
pref label: polar diagram
related: antennaDesign
related: beamwidth
related: radioAntenna
related: sensitivity
related: sidelobe

polarimeter
type: Concept
broader: opticalInstrument
broader: telescopeInstrument
definition: polarimeter
pref label: polarimeter
related: photometer
related: polarimetry

polarimetry
type: Concept
broader: astronomicalTechnique
broader: observingTechnique
definition: polarimetry
pref label: polarimetry
related: lightPolarization
related: photometry
related: polarimeter

polarizationChargeSeparation
type: Concept
broader: magnetoOpticalEffect
definition: polarization [charge separation]
pref label: polarization charge separation
related: anisotropy
related: ion

polarizedLight
type: Concept
alt label: polarised light UK
broader: electromagneticRadiation
broader: visibleRadiation
definition: polarized light
pref label: polarized light
related: lightPolarization

polarizedRadiation
type: Concept
broader: electromagneticRadiation
broader: radiation
definition: polarized radiation
pref label: polarized radiation
related: FaradayEffect
related: XRayPolarization
related: lightPolarization
related: stokesParameter

polarMotion
type: Concept
broader: motion
definition: polar motion
pref label: polar motion
related: ChandlerWobble
related: EarthRotation
related: latitudeVariation
related: nutation
related: precession

polarOrbit
type: Concept
broader: orbit
definition: polar orbit
pref label: polar orbit
related: artificialSatellite

polarRegion
type: Concept
definition: polar region
pref label: polar region
related: planet

polarTide
type: Concept
broader: tide
definition: polar tide
pref label: polar tide

pole
type: Concept
definition: pole
narrower: GalacticPole
narrower: celestialPole
narrower: eclipticPole
narrower: nadir
narrower: zenith
pref label: pole

polishing
type: Concept
definition: polishing
narrower: figuring
pref label: polishing
related: lens
related: mirror
related: opticalSurface

pollution
type: Concept
definition: pollution
narrower: airPollution
narrower: lightPollution
narrower: spacePollution
pref label: pollution
related: greenhouseEffect
related: siteTesting

polonium
type: Concept
alt label: Po
broader: fundamentalChemicalElement
definition: polonium (atomic number 84)
history note: FVH: new (2007-OCT-25)
pref label: polonium

polycyclicHydrocarbon
type: Concept
broader: hydrocarbon
definition: polycyclic hydrocarbon
pref label: polycyclic hydrocarbon

polytrope
type: Concept
definition: polytrope
pref label: polytrope
related: model
related: stellarStructure

populationIiCepheid
type: Concept
broader: populationIiStar
definition: Population II Cepheid
narrower: RrLyraeStar
narrower: WVirginisStar
pref label: population II Cepheid

populationIiiStar
type: Concept
alt label: PopIII
broader: metalPoorStar
broader: oldStar
broader: star
definition: Population III star
history note: FVH: new (2007-SEP-21)
narrower: haloStar
pref label: population III star
related: GalacticHalo
related: globularStarCluster
related: stellarPopulation

populationIiStar
type: Concept
alt label: Pop II star
alt label: PopII
broader: metalPoorStar
broader: oldStar
broader: star
definition: Population II star
narrower: SxPhoenicisStar
narrower: diskPopulation
narrower: diskStar
narrower: haloStar
narrower: horizontalBranchStar
narrower: populationIiCepheid
pref label: population II star
related: GalacticHalo
related: galacticNucleus
related: globularStarCluster
related: intermediatePopulationStar
related: stellarPopulation
related: subluminousStar

populationInversion
type: Concept
definition: population inversion
pref label: population inversion
related: atomicProcess
related: laser
related: maser
related: stimulatedEmission

populationIStar
type: Concept
alt label: PopI
broader: star
definition: Population I star
narrower: extremePopulationIStar
narrower: youngStar
pref label: population I star
related: openStarCluster
related: spiralArm
related: stellarPopulation
related: youngStarCluster

positionAngle
type: Concept
broader: orbitalElement
definition: position angle
pref label: position angle
related: binaryStar
related: orbit
related: orientation

position
type: Concept
definition: position
narrower: apparentPosition
narrower: truePosition
pref label: position
related: coordinateSystem
related: fundamentalSystem
related: referenceSystem
related: sphericalCoordinate
related: standardStar
scope note: combine with other terms

positionSensitiveProportionalCounter
type: Concept
alt label: PSPC
broader: proportionalCounter
definition: position-sensitive proportional counter
history note: FVH: new (2007-SEP-21)
pref label: position sensitive proportional counter

positron
type: Concept
broader: antiparticle
broader: lepton
broader: nuclearRadiation
broader: particle
definition: positron
pref label: positron
related: electron
related: pairAnnihilation
related: pairProduction
related: radioactivity

postAsymptoticGiantBranch
type: Concept
alt label: post-AGB
definition: post-asymptotic giant branch
history note: APM: new (2007-OCT-4)
narrower: UuHerculisStar
pref label: post-asymptotic giant branch
related: HertzsprungRussellDiagram
related: asymptoticGiantBranch
related: lateTypeGiant

postMainSequenceStar
type: Concept
alt label: post main sequence star
broader: evolvedStar
broader: nonMainSequenceStar
definition: post-main sequence star
narrower: giant
narrower: subgiant
narrower: supergiant
pref label: post-main sequence star
scope note: only the broad classes are shown below; specific type will be found under these, or from the hierarchical list; excluding advanced evolution

potassium
type: Concept
alt label: K
broader: fundamentalChemicalElement
definition: potassium (atomic number 19)
history note: FVH: new (2007-OCT-25)
pref label: potassium

potentialEnergy
type: Concept
broader: energy
definition: potential energy
pref label: potential energy
related: kineticEnergy

potentialTheory
type: Concept
definition: potential theory
pref label: potential theory
scope note: in mathematics

power
type: Concept
definition: power
pref label: power
scope note: combine with other terms

PoyntingRobertsonEffect
type: Concept
alt label: Poynting Robertson effect
definition: Poynting-Robertson effect
pref label: Poynting-Robertson effect
related: radiationPressure
related: solarWind
related: stellarWind

pProcess
type: Concept
definition: p-process
pref label: p process
related: nucleosynthesis
related: rProcess
related: sProcess
related: supernova

praseodymium
type: Concept
alt label: Pr
broader: fundamentalChemicalElement
broader: rareEarth
definition: praseodymium (atomic number 59)
history note: FVH: new (2007-OCT-25)
pref label: praseodymium

preamplifier
type: Concept
broader: amplifier
definition: preamplifier
pref label: preamplifier

precession
type: Concept
definition: precession
pref label: precession
related: EarthRotation
related: astrometry
related: celestialMechanics
related: equationOfTheEquinox
related: nutation
related: obliquityOfEcliptic
related: polarMotion
related: superhump

precision
type: Concept
definition: precision
pref label: precision
related: limitingMagnitude
related: sensitivity
scope note: combine with other terms

precursorPulse
type: Concept
definition: precursor pulse
pref label: precursor pulse
related: pulsar

prediction
type: Concept
definition: prediction
pref label: prediction
related: forecasts
scope note: combine with other terms

preGalacticStar
type: Concept
alt label: pregalactic star
broader: oldStar
definition: pre-Galactic star
pref label: pre-Galactic star

preMainSequenceStar
type: Concept
alt label: early stage star
alt label: premainsequence star
broader: nonMainSequenceStar
broader: youngStar
definition: pre-main sequence star
narrower: HerbigHaroObject
narrower: RwAurigaeStar
narrower: TTauriStar
narrower: flashStar
narrower: protostar
pref label: pre-main sequence star
related: TAssociation
related: orionPopulationStar
related: starFormation

preNova
type: Concept
alt label: prenova
broader: progenitor
definition: pre-nova
pref label: pre-nova
related: nova

preSolarNebula
type: Concept
alt label: presolar nebula
definition: pre-solar nebula
pref label: pre-solar nebula
related: SolarSystem

pressureBroadening
type: Concept
broader: lineBroadening
definition: pressure broadening
pref label: pressure broadening
related: DopplerBroadening
related: ZeemanSplitting
related: lineSpectrum
related: naturalLineWidth
related: spectroscopy

pressure
type: Concept
definition: pressure
pref label: pressure
related: RankineHugoniotRelation
related: barometer
related: radiationPressure
related: vacuum
scope note: combine with other terms

preSupernova
type: Concept
alt label: presupernova
broader: progenitor
definition: pre-supernova
pref label: pre-supernova
related: supernova

primaryLens
type: Concept
broader: lens
broader: objective
definition: primary lens
pref label: primary lens
related: refractingTelescope

primaryMirror
type: Concept
broader: mirror
broader: objective
broader: telescopeMirror
definition: primary mirror
pref label: primary mirror
related: reflectingTelescope
related: secondaryMirror
related: tertiaryMirror

primaryStar
type: Concept
broader: companionStar
definition: primary star
history note: ES: new (2007-OCT-8)
pref label: primary star
related: secondaryStar
related: tertiaryStar

primeFocus
type: Concept
broader: focus
definition: prime focus
pref label: prime focus
related: CassegrainFocus
related: CoudeFocus
related: NasmythFocus

primordialFireball
type: Concept
broader: cosmology
definition: primordial fireball
pref label: primordial fireball
related: BigBangTheory

primordialGalaxy
type: Concept
broader: galaxy
definition: primordial galaxy
pref label: primordial galaxy

prism
type: Concept
definition: prism
narrower: objectivePrism
pref label: prism
related: grism
related: opticalInstrument
related: prismSpectrograph
related: spectrograph
related: spectrum

prismSpectrograph
type: Concept
broader: spectrograph
definition: prism spectrograph
pref label: prism spectrograph
related: gratingSpectrograph
related: prism

profile
type: Concept
definition: profile
narrower: lineProfile
pref label: profile

progenitor
type: Concept
alt label: precursors
definition: progenitor
narrower: preNova
narrower: preSupernova
pref label: progenitor
related: nova
related: supernova

promethium
type: Concept
alt label: Pm
broader: fundamentalChemicalElement
definition: promethium (atomic number 61)
history note: FVH: new (2007-OCT-25)
pref label: promethium

prominence
type: Concept
alt label: chromospheric eruption
definition: prominence
narrower: activeProminence
narrower: quiescentProminence
pref label: prominence
related: HanleEffect
related: Sun
related: chromosphere
related: flare
related: opticalFlare
related: solarActivity
related: solarFilament
related: sunspot

propagation
type: Concept
definition: propagation
pref label: propagation
scope note: combine with other terms

properMotion
type: Concept
broader: motion
broader: spaceMotion
definition: proper motion
pref label: proper motion
related: GalacticRotation
related: LocalStandardOfRest
related: kinematics
related: movingClusterParallax
related: peculiarMotion
related: photographicAstrometry
related: radialVelocity
related: radiantMovingCluster
related: secularParallax
related: stellarDynamics
related: stellarMotion
related: transverseVelocity

property
type: Concept
definition: property
narrower: magneticProperty
narrower: mechanicalProperty
narrower: opticalProperty
narrower: surfaceProperty
narrower: thermalProperty
pref label: property
scope note: combine with other terms

proportionalCounter
type: Concept
broader: measuringInstrument
change note: FVH: added NT POSITION_SENSITIVE_PROPORTIONAL_COUNTERS (2007-SEP-21)
definition: proportional counter
narrower: positionSensitiveProportionalCounter
pref label: proportional counter
related: XRayDetector

protactinium
type: Concept
alt label: Pa
broader: fundamentalChemicalElement
definition: protactinium (atomic number 91)
history note: FVH: new (2007-OCT-25)
pref label: protactinium

protocluster
type: Concept
broader: cluster
definition: protocluster
pref label: protocluster
related: collapsingCloud
related: cosmogony
related: cosmology
related: galaxyCluster
related: starCluster

protogalaxy
type: Concept
broader: galaxy
broader: gaseousSphere
definition: protogalaxy
pref label: protogalaxy
related: collapsingCloud
related: cosmogony
related: cosmology

proton
type: Concept
broader: elementaryParticle
broader: fundamentalParticle
broader: particle
definition: proton
pref label: proton
related: alphaParticle
related: antiproton
related: nucleusAtom

protonProtonReaction
type: Concept
alt label: proton proton cycle
alt label: proton proton reaction
alt label: proton-proton cycle
broader: hydrogenBurning
definition: proton-proton reaction
pref label: proton-proton reaction
related: carbonNitrogenCycle
related: nuclearFusion
related: stellarInterior

protoplanetaryNebula
type: Concept
alt label: proplyds
broader: collapsingCloud
change note: FVH: added ALT proplyd (2007-SEP-21)
definition: protoplanetary nebula
pref label: protoplanetary nebula
related: cosmogony
related: protoplanet
related: solarNebula

protoplanet
type: Concept
definition: protoplanet
pref label: protoplanet
related: SolarSystem
related: planet
related: planetesimal
related: protoplanetaryNebula
related: satellite
related: solarNebula

protostar
type: Concept
broader: gaseousSphere
broader: preMainSequenceStar
definition: protostar
pref label: protostar
related: BokGlobule
related: HerbigHaroObject
related: TTauriStar
related: birthRate
related: collapsingCloud
related: cometaryGlobule
related: starFormation
related: stellarEvolution

pulsar
type: Concept
broader: collapsedStar
broader: degenerateStar
broader: evolvedStar
broader: radioSource
broader: relativisticStar
definition: pulsar
narrower: XRayPulsar
narrower: binaryPulsar
narrower: opticalPulsar
narrower: radioPulsar
pref label: pulsar
related: frequencyShift
related: glitch
related: neutronStar
related: precursorPulse
related: pulseDuration
related: pulseEnergy
related: pulseIntensity
related: pulseProfile
related: pulseStructure
related: pulseWidth
related: pulseWindow
related: rapidOscillation
related: supernova
related: supernovaRemnant

pulsatingVariableStar
type: Concept
broader: intrinsicVariableStar
broader: variableStar
definition: pulsating variable star
narrower: 53PerseiStar
narrower: BlHerculisStar
narrower: Cepheid
narrower: MiraVariableStar
narrower: RrLyraeStar
narrower: RvTauriStar
narrower: SVulpeculaeStar
narrower: SxPhoenicisStar
narrower: WVirginisStar
narrower: ZzCetiStar
narrower: betaCepheiStar
narrower: deltaDelphiniStar
narrower: deltaScutiStar
narrower: doubleModeCepheid
narrower: doubleModeVariableStar
narrower: dwarfCepheid
narrower: irregularVariableStar
narrower: lambdaEridaniStar
narrower: longPeriodVariableStar
narrower: multiPeriodicVariableStar
narrower: periodicVariableStar
narrower: semiRegularVariableStar
pref label: pulsating variable star
related: HeIiIonizationZone
related: asteroseismology
related: doubleModePulsation
related: kappaMechanism
related: multiPeriodicPulsation
related: nonRadialPulsation
related: overtoneMode
related: period
related: periodChange
related: periodColorRelation
related: periodDensityRelation
related: periodLuminosityColorRelation
related: periodLuminosityRelation
related: periodMassRelation
related: periodRadiusRelation
related: periodSpectrumRelation
related: pulsationMode
related: pulsationTheory

pulsationMode
type: Concept
definition: pulsation mode
narrower: fundamentalMode
narrower: overtoneMode
pref label: pulsation mode
related: multiPeriodicPulsation
related: multiPeriodicVariableStar
related: nonRadialPulsation
related: period
related: pulsatingVariableStar
related: pulsation
related: pulsationTheory

pulsation
type: Concept
definition: pulsation
pref label: pulsation
related: amplitude
related: asteroseismology
related: pulsationMode
scope note: combine with other terms

pulsationTheory
type: Concept
definition: pulsation theory
pref label: pulsation theory
related: HeIiIonizationZone
related: pulsatingVariableStar
related: pulsationMode

pulseCounter
type: Concept
definition: pulse counter
pref label: pulse counter
related: amplifier
related: pulse

pulseCounting
type: Concept
definition: pulse counting
pref label: pulse counting
related: amplifier
related: pulse

pulseDuration
type: Concept
definition: pulse duration
pref label: pulse duration
related: pulsar
related: pulse

pulseEnergy
type: Concept
definition: pulse energy
pref label: pulse energy
related: pulsar
related: pulse

pulseIntensity
type: Concept
definition: pulse intensity
pref label: pulse intensity
related: pulsar
related: pulse

pulseProfile
type: Concept
definition: pulse profile
pref label: pulse profile
related: pulsar
related: pulse

pulse
type: Concept
definition: pulse
pref label: pulse
related: pulseCounter
related: pulseCounting
related: pulseDuration
related: pulseEnergy
related: pulseIntensity
related: pulseProfile
related: pulseStructure
related: pulseWidth
related: pulseWindow
scope note: combine with other terms

pulseStructure
type: Concept
definition: pulse structure
pref label: pulse structure
related: pulsar
related: pulse

pulseWidth
type: Concept
definition: pulse width
pref label: pulse width
related: pulsar
related: pulse

pulseWindow
type: Concept
definition: pulse window
pref label: pulse window
related: pulsar
related: pulse

PurkinjeEffect
type: Concept
definition: Purkinje effect
pref label: Purkinje effect
related: photometry
related: variableStar
related: visualMagnitude
related: visualObservation

qBranch
type: Concept
definition: q-branch
pref label: q branch
related: molecularSpectrum
related: vibrationalSpectrum

QMagnitude
type: Concept
broader: apparentMagnitude
definition: Q magnitude
pref label: Q magnitude
related: farInfraredRadiation
related: infraredPhotometry

quadrantDetector
type: Concept
definition: quadrant detector
pref label: quadrant detector
related: autoguider
related: controlSystem
related: guideSystem
related: photomultiplierTube

quadrant
type: Concept
broader: astrometricInstrument
broader: instrument
definition: quadrant
pref label: quadrant
related: meridianCircle

quadrature
type: Concept
definition: quadrature
pref label: quadrature
related: conjunction
related: opposition

quanta
type: Concept
alt label: quantum
definition: quanta
pref label: quanta
related: photon
related: quantumTheory

quantization
type: Concept
alt label: quantisation UK
definition: quantization
pref label: quantization
related: analysis
related: determination
related: measurement

quantumCosmology
type: Concept
broader: cosmology
definition: quantum cosmology
pref label: quantum cosmology
related: nakedSingularity
related: spaceTimeSingularity

quantumEfficiency
type: Concept
alt label: Q.E.
alt label: QE
definition: quantum efficiency
pref label: quantum efficiency
related: cathode
related: chargeCoupledDevice
related: detector
related: imageTube
related: photographicEmulsion
related: photomultiplierTube

quantumFieldTheory
type: Concept
definition: quantum field theory
pref label: quantum field theory
related: electromagneticField
related: gravitationalField
related: quantumTheory

quantumMechanics
type: Concept
definition: quantum mechanics
pref label: quantum mechanics
related: FermiDiracStatistics
related: quantumTheory
related: relativisticVelocity
related: superconductingTunnelJunction

quantumTheory
type: Concept
definition: quantum theory
pref label: quantum theory
related: quanta
related: quantumFieldTheory
related: quantumMechanics

quark
type: Concept
broader: elementaryParticle
definition: quark
pref label: quark
related: baryon
related: lepton
related: meson
related: neutronStar

quarterWavePlate
type: Concept
definition: quarter-wave plate
history note: FVH: new (2007-SEP-21)
pref label: quarter wave plate
related: circularPolarization
related: halfWavePlate

quasarGalaxyPair
type: Concept
definition: quasar-galaxy pair
pref label: quasar galaxy pair
related: galaxy
related: quasar

quasarMicrolensing
type: Concept
broader: gravitationalMicrolensing
definition: microlensing of AGN nucleus
history note: FVH: new (2007-OCT-8)
pref label: quasar microlensing
related: quasar

quasar
type: Concept
alt label: QSO
alt label: quasi-stellar galaxy
alt label: quasi-stellar object
alt label: quasi-stellar radio_source
broader: extragalacticObject
broader: extragalacticRadioSource
definition: quasar
narrower: XRayQuasar
narrower: radioQuietQuasar
pref label: quasar
related: BlLacertaeObject
related: LymanAlphaForest
related: XRaySource
related: absorptionLineSystem
related: activeGalacticNucleus
related: blazar
related: compactGalaxy
related: doubleQuasar
related: linerGalaxy
related: luminousArc
related: quasarGalaxyPair
related: quasarMicrolensing
related: variableSource

quiescentProminence
type: Concept
broader: prominence
definition: quiescent prominence
pref label: quiescent prominence
related: Sun
related: chromosphere

quietSun
type: Concept
definition: quiet Sun
pref label: quiet Sun
related: activeSun
related: solarCycle

radarAstronomy
type: Concept
broader: radioAstronomy
definition: radar astronomy
pref label: radar astronomy
related: radar
related: radarEquipment
related: radarTelescope
related: radioObservatory

radarEquipment
type: Concept
definition: radar equipment
narrower: antenna
pref label: radar equipment
related: radarAstronomy
related: radioTelescope

radarMapping
type: Concept
definition: radar mapping
pref label: radar mapping
related: map

radar
type: Concept
definition: radar
narrower: opticalRadar
pref label: radar
related: DopplerEffect
related: antenna
related: radarAstronomy

radarTelescope
type: Concept
broader: radioTelescope
definition: radar telescope
pref label: radar telescope
related: dishAntenna
related: parabolicReflector
related: radarAstronomy

radialPulsation
type: Concept
definition: radial pulsation
pref label: radial pulsation
related: BlHerculisStar
related: Cepheid
related: HeIiIonizationZone
related: MiraVariableStar
related: RvTauriStar
related: betaCepheiStar
related: deltaScutiStar

radialVelocity
type: Concept
broader: spaceMotion
broader: velocity
definition: radial velocity
narrower: iodineCell
pref label: radial velocity
related: DopplerEffect
related: kinematics
related: lineShift
related: peculiarMotion
related: peculiarVelocity
related: properMotion
related: redshift
related: spectroscopy
related: stellarDynamics
related: stellarMotion
related: tangentialVelocity
related: transverseVelocity
related: virialTheorem

radiantMeteor
type: Concept
definition: radiant [meteor]
pref label: radiant meteor
related: meteor
related: meteorShower
related: meteorStream
related: meteorTrail

radiantMovingCluster
type: Concept
definition: radiant [moving cluster]
pref label: radiant moving cluster
related: movingClusterParallax
related: openStarCluster
related: properMotion

radiationBelt
type: Concept
definition: radiation belt
narrower: vanAllenRadiationBelt
pref label: radiation belt
related: Earth
related: atmosphere
related: plasma

radiationDamping
type: Concept
definition: radiation damping
pref label: radiation damping
related: dampingConstant
related: decayOscillation
related: radiativeBraking

radiationField
type: Concept
definition: radiation field
pref label: radiation field
related: electromagneticField

radiationMechanism
type: Concept
definition: radiation mechanism
narrower: freeBoundEmission
narrower: freeFreeEmission
pref label: radiation mechanism
related: CerenkovRadiation
related: RayleighLimit
related: bremsstrahlung
related: cyclotronRadiation
related: gravitationalRadiation
related: nonLteTransfer
related: relativisticParticle
related: relativisticPlasma
related: synchrotronRadiation

radiationPressure
type: Concept
definition: radiation pressure
pref label: radiation pressure
related: EddingtonLimit
related: PoyntingRobertsonEffect
related: photon
related: pressure
related: solarWind
related: stellarWind

radiation
type: Concept
change note: FVH: moved lots of NT's to electromagnetic_radiation (2007-OCT-8)
definition: radiation
narrower: CerenkovRadiation
narrower: XRayRadiation
narrower: backgroundRadiation
narrower: continuumRadiation
narrower: cosmicRay
narrower: cyclotronRadiation
narrower: electromagneticRadiation
narrower: gammaRayRadiation
narrower: gravitationalRadiation
narrower: highEnergyRadiation
narrower: infraredRadiation
narrower: polarizedRadiation
narrower: synchrotronRadiation
narrower: thermalRadiation
narrower: ultravioletRadiation
pref label: radiation
related: PlanckBlackBodyFormula
related: absorption
related: albedo
related: bolometer
related: effectiveTemperature
related: emissivity
related: energyTransfer
related: fluxDensity
related: illumination
related: irradiance
related: opacity
related: photon
related: radiativeEquilibrium
related: recombinationLine
related: solarConstant
scope note: combine with other terms

radiationScattering
type: Concept
alt label: electromagnetic wave scattering
definition: radiation scattering
narrower: ComptonScattering
narrower: RayleighScattering
narrower: ThomsonScattering
narrower: XRayScattering
narrower: lightScattering
pref label: radiation scattering
related: ComptonEffect
related: RamanEffect
related: electrostaticWave
related: elementaryParticleScattering
related: lightPolarization
related: phaseFunction
related: photon
related: scattering
related: zodiacalLight

radiativeBraking
type: Concept
definition: radiative braking
pref label: radiative braking
related: dampingConstant
related: dynamicalFriction
related: radiationDamping
related: rotatingStar

radiativeEquilibrium
type: Concept
definition: radiative equilibrium
pref label: radiative equilibrium
related: absorption
related: electromagneticRadiation
related: radiation
related: temperature

radiativeRecombination
type: Concept
alt label: radiative capture
definition: radiative recombination
pref label: radiative recombination
related: airglow
related: electron
related: photon
related: plasma

radiativeTransfer
type: Concept
broader: energyTransfer
definition: radiative transfer
pref label: radiative transfer
related: RayleighLimit
related: opacity
related: transportProcess

radical
type: Concept
broader: compositeParticle
definition: radical
narrower: hydroxylRadical
pref label: radical
related: ion

radioAbsorption
type: Concept
definition: radio absorption
pref label: radio absorption
related: HIRegion
related: interstellarMatter
related: ionosphere

radioactiveDecay
type: Concept
definition: radioactive decay
pref label: radioactive decay
related: radioactivity

radioactivity
type: Concept
definition: radioactivity
pref label: radioactivity
related: alphaParticle
related: electron
related: gammaRayRadiation
related: nuclearFission
related: positron
related: radioactiveDecay

radioAntenna
type: Concept
alt label: radio antennas
broader: antenna
definition: radio antennas
pref label: radio antenna
related: polarDiagram
related: radioTelescope
related: sidelobe

radioAstrometry
type: Concept
broader: astrometry
broader: observingTechnique
broader: radioAstronomy
definition: radio astrometry
pref label: radio astrometry
related: interferometry
related: longBaselineInterferometry
related: veryLongBaselineInterferometry

radioAstronomy
type: Concept
definition: radio astronomy
narrower: millimeterAstronomy
narrower: radarAstronomy
narrower: radioAstrometry
narrower: submillimeterAstronomy
pref label: radio astronomy
related: cleanMethod
scope note: use as nts all terms associated with radio astronomy

radioBackground
type: Concept
alt label: radio frequency interference
alt label: radio noise
broader: backgroundRadiation
definition: radio background
pref label: radio background
related: XRayBackground
related: cosmicNoise
related: gammaRayBackground
related: microwaveBackground
related: radioInterference
related: radioRadiation
related: ultravioletBackground

radioBurst
type: Concept
broader: burst
definition: radio burst
pref label: radio burst
related: XRayBurst
related: burster
related: gammaRayBurst
related: opticalBurst

radioCore
type: Concept
definition: radio core
pref label: radio core
related: radioSource

radioEmission
type: Concept
broader: emissionSpectrum
definition: radio emission
pref label: radio emission
scope note: see radio radiation

radioFlare
type: Concept
broader: flare
definition: radio flare
pref label: radio flare
related: flareStar

radioFrequency
type: Concept
definition: radio frequency
pref label: radio frequency
related: 21CmLine
related: PaulTrap
related: radioRadiation
related: radioSpectrum
related: spectralIndex

radioGalaxy
type: Concept
broader: extragalacticRadioSource
broader: galaxy
definition: radio galaxy
narrower: EpGalaxy
narrower: giantRadioGalaxy
narrower: headTailGalaxy
pref label: radio galaxy
related: FanaroffRileyClass
related: XRaySource
related: activeGalacticNucleus

radioheliograph
type: Concept
broader: radioTelescope
broader: solarTelescope
definition: radioheliograph
pref label: radioheliograph

radioInterference
type: Concept
alt label: radio frequency interference
alt label: radio noise
definition: radio interference
narrower: cosmicNoise
pref label: radio interference
related: radioBackground

radioInterferometer
type: Concept
broader: interferometer
broader: radioTelescope
definition: radio interferometer
narrower: longBaselineInterferometer
narrower: tArray
narrower: veryLongBaselineInterferometer
narrower: yArray
pref label: radio interferometer
related: array
related: pencilBeam
related: phasedArray
related: radioInterferometry
related: radioObservatory

radioInterferometry
type: Concept
broader: interferometry
broader: observingTechnique
definition: radio interferometry
narrower: longBaselineInterferometry
narrower: veryLongBaselineInterferometry
pref label: radio interferometry
related: interferenceWave
related: radioInterferometer
related: timeSynchronization
scope note: see radio interferometer

radioJet
type: Concept
broader: jet
definition: radio jet
pref label: radio jet
related: radioSource

radiometer
type: Concept
broader: detector
broader: measuringInstrument
definition: radiometer
narrower: DickeRadiometer
pref label: radiometer
related: bolometer
related: photometer
related: radiometry

radiometry
type: Concept
definition: radiometry
pref label: radiometry
related: radiometer

radioObservatory
type: Concept
broader: observatory
definition: radio observatory
pref label: radio observatory
related: millimeterAstronomy
related: radarAstronomy
related: radioInterferometer
related: radioTelescope
related: submillimeterAstronomy

radioOccultation
type: Concept
broader: occultation
definition: radio occultation
pref label: radio occultation

radioPulsar
type: Concept
broader: pulsar
definition: radio pulsar
pref label: radio pulsar
related: opticalPulsar

radioQuietQuasar
type: Concept
broader: quasar
definition: radio quiet quasar
pref label: radio quiet quasar

radioRadiation
type: Concept
alt label: radio wave
broader: electromagneticRadiation
change note: FVH: moved BT radiation to BT electromagnetic_radiation and radio_wave to ALT (2007-OCT-8)
definition: radio radiation
pref label: radio radiation
related: Jansky
related: radioBackground
related: radioFrequency
related: radioSource
scope note: synonym: radio emission

radioRecombinationLine
type: Concept
broader: recombinationLine
definition: radio recombination line
narrower: 21CmLine
pref label: radio recombination line
related: HIRegion
related: HIiRegion
related: maser

radioSourceCatalog
type: Concept
broader: catalog
definition: radio source catalog
pref label: radio source catalog
related: radioSourceCount
scope note: combine with other terms

radioSourceCount
type: Concept
definition: radio source count
pref label: radio source count
related: observationalCosmology
related: radioSource
related: radioSourceCatalog
related: statistics
related: survey

radioSource
type: Concept
broader: source
definition: radio source
narrower: OhSource
narrower: compactSource
narrower: discreteRadioSource
narrower: extendedSource
narrower: extragalacticRadioSource
narrower: headTailGalaxy
narrower: pulsar
narrower: radioStar
narrower: variableSource
pref label: radio source
related: SiOMaser
related: bipolarOutflow
related: galaxyEncounter
related: interplanetaryScintillation
related: interstellarScintillation
related: ionosphericScintillation
related: jet
related: lobe
related: maser
related: opticalIdentification
related: radioCore
related: radioJet
related: radioRadiation
related: radioSourceCount
related: supernovaRemnant
scope note: only the broad classes are shown below; specific type will be found under these, or from the hierarchical list

radioSpectrograph
type: Concept
alt label: radio spectrometer
broader: spectrograph
definition: radio spectrograph
pref label: radio spectrograph
related: radioSpectroscopy
related: radioSpectrum

radioSpectroscopy
type: Concept
definition: radio spectroscopy
pref label: radio spectroscopy
related: radioSpectrograph
related: radioSpectrum

radioSpectrum
type: Concept
broader: spectrum
definition: radio spectrum
pref label: radio spectrum
related: microwaveSpectrum
related: radioFrequency
related: radioSpectrograph
related: radioSpectroscopy
related: spectralIndex

radioStar
type: Concept
broader: radioSource
definition: radio star
narrower: flareStar
pref label: radio star
related: XRayStar

radioStructure
type: Concept
definition: radio structure
narrower: lobe
pref label: radio structure
related: bipolarOutflow
related: compactSource
related: contourMap
related: driftScan
related: extendedSource
related: headTailGalaxy

radioTelescope
type: Concept
broader: telescope
definition: radio telescope
narrower: CassegrainAntenna
narrower: MillsCrossAntenna
narrower: YagiAntenna
narrower: dishAntenna
narrower: radarTelescope
narrower: radioInterferometer
narrower: radioheliograph
narrower: veryLongBaselineInterferometer
pref label: radio telescope
related: antenna
related: antennaDesign
related: apodization
related: array
related: beamSwitching
related: beamwidth
related: feedHorn
related: halfWaveDipole
related: interferometer
related: parabolicReflector
related: phaseRotator
related: phaseSwitching
related: radarEquipment
related: radioAntenna
related: radioObservatory
related: receiver
related: shapedReflector
related: subreflector
scope note: not a complete list of terms

radioTransmissionWindow
type: Concept
broader: atmosphericWindow
change note: FVH: renamed to avoid confusion with optics (2007-NOV-2)
definition: radio transmission window through the atmosphere
pref label: radio transmission window
related: infraredTransmissionWindow
related: interstellarMatter
related: opticalTransmissionWindow
scope note: low absorption in atmosphere

radioWaveguide
type: Concept
broader: waveguide
definition: radio waveguide
narrower: hornAntenna
pref label: radio waveguide

radium
type: Concept
alt label: Ra
broader: fundamentalChemicalElement
definition: radium (atomic number 88)
history note: FVH: new (2007-OCT-25)
pref label: radium

radiusLuminosityRelation
type: Concept
alt label: radius luminosity relation
broader: statisticalRelation
definition: radius-luminosity relation
narrower: fundamentalPlane
pref label: radius-luminosity relation
related: Cepheid
related: periodColorRelation
related: periodDensityRelation
related: periodLuminosityColorRelation
related: periodLuminosityRelation
related: periodMassRelation
related: periodRadiusRelation
related: periodSpectrumRelation

radon
type: Concept
alt label: Rn
broader: fundamentalChemicalElement
definition: radon (atomic number 86)
history note: FVH: new (2007-OCT-25)
pref label: radon

RaidArray
type: Concept
broader: dataStorage
definition: RAID array of hard disk
history note: FVH: new (2007-NOV-2)
pref label: RAID array

RamanEffect
type: Concept
definition: Raman effect
pref label: Raman effect
related: RamanScattering
related: RamanSpectroscopy
related: RamanSpectrum
related: absorptionSpectrum
related: emissionSpectrum
related: radiationScattering

RamanScattering
type: Concept
definition: Raman scattering
pref label: Raman scattering
related: RamanEffect
scope note: see Raman effect

RamanSpectroscopy
type: Concept
broader: spectroscopy
definition: Raman spectroscopy
pref label: Raman spectroscopy
related: RamanEffect
related: molecularSpectrum
scope note: see Raman effect

RamanSpectrum
type: Concept
definition: Raman spectrum
pref label: Raman spectrum
related: RamanEffect
related: lightScattering
scope note: see Raman effect

RamsdenEyepiece
type: Concept
broader: eyepiece
definition: Ramsden eyepiece
pref label: Ramsden eyepiece

rangeFinder
type: Concept
broader: measuringInstrument
definition: range finder
pref label: range finder
related: distance

RankineHugoniotRelation
type: Concept
definition: Rankine-Hugoniot relation
pref label: Rankine-Hugoniot relation
related: density
related: pressure
related: shockWave

rapidBurst
type: Concept
broader: burst
definition: rapid burst
pref label: rapid burst
related: XRayBurst
related: gammaRayBurst

rapidOscillation
type: Concept
definition: rapid oscillation
pref label: rapid oscillation
related: ApStar
related: asteroseismology
related: pulsar

rareEarth
type: Concept
broader: fundamentalChemicalElement
definition: rare earth
narrower: cerium
narrower: dysprosium
narrower: erbium
narrower: europium
narrower: gadolinium
narrower: holmium
narrower: lanthanum
narrower: lutetium
narrower: neodymium
narrower: praseodymium
narrower: samarium
narrower: scandium
narrower: terbium
narrower: thulium
narrower: ytterbium
narrower: yttrium
pref label: rare earth
related: abundance
related: metalAbundance
related: metalLine

RAssociation
type: Concept
alt label: R-association
broader: starAssociation
definition: R association
pref label: R association
related: reflectionNebula
related: youngStar

ratio
type: Concept
definition: ratio
history note: ES: new (2007-OCT-11)
narrower: axialRatio
pref label: ratio

Rayleigh
type: Concept
definition: Rayleigh
pref label: Rayleigh
related: aurora
related: nightSkyBrightness
scope note: solar aurora flux unit

RayleighCriterion
type: Concept
alt label: Rayleigh limit
definition: Rayleigh criterion
pref label: Rayleigh criterion
related: diffraction
related: resolution

RayleighLimit
type: Concept
definition: Rayleigh limit
pref label: Rayleigh limit
related: radiationMechanism
related: radiativeTransfer
scope note: refers to radiation mechanism

RayleighNumber
type: Concept
definition: Rayleigh number
pref label: Rayleigh number
related: convection
related: thermalStability

RayleighScattering
type: Concept
broader: lightScattering
broader: radiationScattering
definition: Rayleigh scattering
pref label: Rayleigh scattering
related: ComptonScattering
related: MieScattering
related: ThomsonScattering
related: airglow
related: interstellarAbsorption
related: nightSkyBrightness

RayleighTaylorInstability
type: Concept
broader: instability
definition: Rayleigh-Taylor instability
pref label: Rayleigh-Taylor instability
related: fluidMechanics

ray
type: Concept
definition: lunar ray
pref label: ray
related: Moon
scope note: refers to lunar feature

RazinEffect
type: Concept
definition: Razin effect
pref label: Razin effect
related: synchrotronRadiation
scope note: also Razin-Tsytovich effect

RCanisMajorisStar
type: Concept
alt label: R CMa star
broader: eclipsingBinaryStar
definition: R Canis Majoris star
pref label: R Canis Majoris star

RCoronaeBorealisStar
type: Concept
alt label: R Cor Bor star
alt label: RCB star
broader: irregularVariableStar
definition: R Coronae Borealis star
pref label: R Coronae Borealis star
related: circumstellarDust
related: circumstellarGrain
related: supergiant

readOutNoise
type: Concept
alt label: RON
broader: noise
definition: read-out noise
history note: FVH: new (2007-SEP-21)
pref label: read out noise
related: chargeCoupledDevice

realAnomaly
type: Concept
broader: orbitalAnomaly
definition: real anomaly
pref label: real anomaly

receiver
type: Concept
definition: receiver
pref label: receiver
related: correlation
related: detector
related: interferometricCorrelation
related: phaseSensitiveDetector
related: phaseSwitching
related: radioTelescope

recombinationLine
type: Concept
broader: emissionLine
definition: recombination line
narrower: radioRecombinationLine
pref label: recombination line
related: electromagneticRadiation
related: radiation
related: recombination
related: spectrum

recombination
type: Concept
definition: recombination
pref label: recombination
related: electron
related: photoionization
related: recombinationLine

recurrentNova
type: Concept
broader: nova
definition: recurrent nova
pref label: recurrent nova
related: fastNova
related: slowNova

reddenedStar
type: Concept
definition: reddened star
pref label: reddened star
related: absorption
related: interstellarAbsorption
related: interstellarReddening
related: reddening
related: reddeningLaw

reddeningLaw
type: Concept
definition: reddening law
pref label: reddening law
related: gasToDustRatio
related: interstellarReddening
related: reddenedStar
related: selectiveAbsorption

reddening
type: Concept
definition: reddening
narrower: interstellarReddening
pref label: reddening
related: absorption
related: intergalacticAbsorption
related: interstellarAbsorption
related: interstellarDust
related: interstellarGas
related: intrinsicColor
related: reddenedStar
related: selectiveAbsorption

redDwarfFlareStar
type: Concept
broader: flareStar
broader: lateTypeDwarf
definition: red dwarf flare star
pref label: red dwarf flare star

redDwarf
type: Concept
definition: red dwarf star
pref label: red dwarf
scope note: see late-type dwarf star

redGiantBump
type: Concept
alt label: red bump
broader: giantBranch
definition: red giant bump
history note: ES: new (2007-OCT-8)
pref label: red giant bump
related: metalRichStar

redGiantClump
type: Concept
alt label: red clump
broader: giantBranch
definition: red giant clump
history note: ES: new (2007-OCT-8)
pref label: red giant clump

redGiant
type: Concept
definition: red giant star
pref label: red giant
scope note: see late-type giant star

redGiantTip
type: Concept
broader: giantBranch
definition: red giant tip
pref label: red giant tip
related: HertzsprungRussellDiagram
related: RgbTipDistance
related: carbonFlash
related: evolvedStar
related: heliumFlash
related: lateTypeGiant

redshiftDistanceRelation
type: Concept
definition: redshift-distance relation
pref label: redshift distance relation
related: DarkEnergy
related: cosmologicalDistanceScale
related: cosmology
related: observationalCosmology

redshiftMagnitudeRelation
type: Concept
definition: redshift-magnitude relation
pref label: redshift magnitude relation
related: DarkEnergy
related: HubbleConstant
related: HubbleDiagram
related: HubbleLaw
related: cosmologicalDistanceScale
related: cosmology

redshift
type: Concept
alt label: red shift
broader: DopplerEffect
broader: lineShift
definition: redshift
narrower: gravitationalRedshift
pref label: redshift
related: HubbleDiagram
related: HubbleLaw
related: LymanAlphaForest
related: TullyFisherRelation
related: cosmologicalDistanceScale
related: cosmology
related: frequencyShift
related: kCorrection
related: observationalCosmology
related: radialVelocity

redStar
type: Concept
definition: red star
pref label: red star
scope note: see either late-type star or reddened star

redSupergiant
type: Concept
definition: red supergiant star
pref label: red supergiant
scope note: see late-type supergiant star

reductionMethod
type: Concept
definition: reduction method
pref label: reduction method
related: analysis
related: astronomicalTechnique
related: dataProcessing
related: dataReduction

referenceFrame
type: Concept
definition: reference frame
pref label: reference frame
related: coordinateSystem

referenceSystem
type: Concept
definition: reference system
pref label: reference system
related: astrometry
related: coordinateSystem
related: position
related: sphericalCoordinate

reflectingTelescope
type: Concept
alt label: reflector
broader: opticalTelescope
definition: reflecting telescope
narrower: BakerNunnCamera
narrower: BouwersTelescope
narrower: MaksutovTelescope
narrower: RitcheyChretienTelescope
narrower: SchmidtTelescope
narrower: coelostat
narrower: multipleMirrorTelescope
narrower: wideFieldTelescope
pref label: reflecting telescope
related: parabolicReflector
related: primaryMirror
related: secondaryMirror
related: tertiaryMirror
scope note: refers to optical telescope

reflectionGrating
type: Concept
broader: diffractionGrating
definition: reflection grating
pref label: reflection grating
related: echelleGrating
related: objectiveGrating
related: transmissionGrating

reflectionNebula
type: Concept
broader: interstellarMatter
broader: nebula
definition: reflection nebula
pref label: reflection nebula
related: RAssociation

reflection
type: Concept
definition: reflection
pref label: reflection
related: albedo
related: mirror
related: refraction
related: scattering
related: thinFilm
related: transmission

reflectorAntenna
type: Concept
alt label: reflector antennas
broader: antenna
definition: reflector antenna
pref label: reflector antenna

refractingTelescope
type: Concept
broader: opticalTelescope
definition: refracting telescope
narrower: zenithTelescope
pref label: refracting telescope
related: primaryLens

refractionAngle
type: Concept
alt label: angle of refraction
definition: angle of refraction
pref label: refraction angle
related: atmosphere
related: zenithDistance
scope note: in Earth's atmosphere

refraction
type: Concept
definition: refraction
pref label: refraction
related: electromagneticRadiation
related: lens
related: reflection
related: refractiveIndex
related: scattering
related: transmission
related: visibleRadiation
related: wavePropagation

refractiveIndex
type: Concept
broader: opticalProperty
definition: refractive index
pref label: refractive index
related: atmosphericRefraction
related: lens
related: opticalPathlength
related: optics
related: refraction

regressionOfNode
type: Concept
definition: regression of node
pref label: regression of node
related: Moon
related: orbitalElement

relativisticAstrophysics
type: Concept
definition: relativistic astrophysics
pref label: relativistic astrophysics
related: blackHole
related: cosmology
related: gravity
related: neutronStar
related: relativisticCosmology

relativisticCosmology
type: Concept
broader: cosmology
definition: relativistic cosmology
pref label: relativistic cosmology
related: relativisticAstrophysics

relativisticDisk
type: Concept
definition: relativistic discs UK
definition: relativistic disk
pref label: relativistic disk
related: relativisticEffect
related: relativisticElectron
related: relativisticPlasma
related: relativity

relativisticEffect
type: Concept
definition: relativistic effect
pref label: relativistic effect
related: relativisticDisk
related: relativisticElectron
related: relativisticPlasma
related: relativity

relativisticElectron
type: Concept
broader: electronBeam
broader: relativisticParticle
definition: relativistic electron
pref label: relativistic electron
related: relativisticDisk
related: relativisticEffect
related: synchrotronRadiation

relativisticFluidDynamics
type: Concept
broader: fluidDynamics
broader: relativisticMechanics
definition: relativistic fluid dynamics
pref label: relativistic fluid dynamics

relativisticMechanics
type: Concept
definition: relativistic mechanics
narrower: relativisticFluidDynamics
pref label: relativistic mechanics
related: relativity

relativisticParticle
type: Concept
broader: particle
definition: relativistic particle
narrower: relativisticElectron
pref label: relativistic particle
related: radiationMechanism

relativisticPlasma
type: Concept
alt label: relativistic gas
broader: gas
broader: plasma
definition: relativistic plasma
pref label: relativistic plasma
related: radiationMechanism
related: relativisticDisk
related: relativisticEffect
related: relativity

relativisticStar
type: Concept
definition: relativistic star
narrower: blackHole
narrower: neutronStar
narrower: pulsar
pref label: relativistic star
related: XRaySource
related: relativity

relativisticVelocity
type: Concept
broader: velocity
definition: relativistic velocity
pref label: relativistic velocity
related: BigBangTheory
related: cosmology
related: quantumMechanics
related: relativity

relativity
type: Concept
broader: cosmogony
definition: relativity
narrower: generalTheoryOfRelativity
pref label: relativity
related: fieldEquation
related: gravitation
related: inertialCoordinateSystem
related: inertialReferenceFrame
related: relativisticDisk
related: relativisticEffect
related: relativisticMechanics
related: relativisticPlasma
related: relativisticStar
related: relativisticVelocity

relaxationTime
type: Concept
definition: relaxation time
pref label: relaxation time
related: age
related: galaxyCluster
related: starCluster
related: stellarDynamics

remoteControlSystem
type: Concept
broader: controlSystem
definition: remote control system
pref label: remote control system
related: automatedTelescope
related: automaticPatrolTelescope
related: telescope
related: telescopeInstrument

remoteSensing
type: Concept
definition: remote sensing
pref label: remote sensing
related: detector
related: infraredRadiation
related: microwaveRadiation

research
type: Concept
definition: research
pref label: research
related: design
related: discoveries
related: observation
related: theory

reseaux
type: Concept
definition: reseaux
pref label: reseaux
related: calibration
related: grid
related: photographicPlate
related: spectroscopy

residualIntensity
type: Concept
definition: residual intensity
pref label: residual intensity
related: absorptionLine
related: lineProfile

resolution
type: Concept
definition: resolution
narrower: angularResolution
narrower: spectralResolution
pref label: resolution
related: RayleighCriterion
related: interferometry
related: optics
related: pixel
related: sensitivity
related: sidelobe
related: visualAcuity

resonanceGap
type: Concept
definition: resonance gap
narrower: KirkwoodGap
pref label: resonance gap
related: asteroid
related: planet
related: planetaryRing
related: shepherdSatellite

resonanceLine
type: Concept
definition: resonance line
narrower: HAlpha
narrower: LymanAlpha
pref label: resonance line
related: spectrum
scope note: not a complete list of terms

retardation
type: Concept
definition: retardation
pref label: retardation
scope note: combine with other terms

reticle
type: Concept
definition: reticle
pref label: reticle
related: eyepiece
related: graticule
related: grid

reticonArray
type: Concept
broader: multiChannelDetector
definition: reticon array
pref label: reticon array
related: diodeArray

rgbPhotometry
type: Concept
alt label: red-green-blue photometry
broader: broadBandPhotometry
broader: photometricSystem
definition: rgb photometry
history note: FVH: new (2007-SEP-21)
pref label: rgb photometry

RgbTipDistance
type: Concept
broader: distanceMeasurement
definition: distance obtained from the tip of the red giant branch
history note: ES: new (2007-OCT-8)
pref label: RGB tip distance
related: redGiantTip

rguPhotometry
type: Concept
broader: broadBandPhotometry
definition: rgu photometry
pref label: rgu photometry

rhenium
type: Concept
alt label: Re
broader: fundamentalChemicalElement
definition: rhenium (atomic number 75)
history note: FVH: new (2007-OCT-25)
pref label: rhenium

rhoCassiopeiaeStar
type: Concept
alt label: rho Cas star
definition: rho Cassiopeiae star
pref label: rho Cassiopeiae star

rhodium
type: Concept
alt label: Rh
broader: fundamentalChemicalElement
definition: rhodium (atomic number 45)
history note: FVH: new (2007-OCT-25)
pref label: rhodium

RightAscension
type: Concept
alt label: celestial longitude
broader: equatorialCoordinateSystem
broader: longitude
definition: Right Ascension
pref label: Right Ascension
related: Declination
related: celestialEquator
related: equator
related: hourAngle
related: transitTime

rigidBodyRotation
type: Concept
broader: rotation
definition: rigid body rotation
pref label: rigid body rotation
related: rotatingBody

rill
type: Concept
definition: rill
pref label: rill
related: planet
related: satellite

ringDivision
type: Concept
definition: ring division
pref label: ring division
related: planet
related: planetaryRing

ringGalaxy
type: Concept
broader: galaxy
broader: peculiarGalaxy
definition: ring galaxy
pref label: ring galaxy
related: ring

ringNebula
type: Concept
broader: nebula
definition: ring nebula
pref label: ring nebula
related: planetaryNebula

ring
type: Concept
definition: ring
narrower: planetaryRing
narrower: stellarRing
pref label: ring
related: ansa
related: ringGalaxy

RitcheyChretienTelescope
type: Concept
alt label: RC
broader: reflectingTelescope
definition: Ritchey-Chretien telescope
pref label: Ritchey-Chretien telescope

RMagnitude
type: Concept
broader: apparentMagnitude
definition: R magnitude
pref label: R magnitude
related: BesselPhotometry
related: JohnsonPhotometry
related: KronCousinsPhotometry

RocheLimit
type: Concept
definition: Roche limit
pref label: Roche limit
related: closeBinaryStar
related: gravitation
related: orbit
related: planet
related: planetaryRing
related: tidalDisruption

RocheLobe
type: Concept
definition: Roche lobe
pref label: Roche lobe
related: closeBinaryStar
related: eclipsingBinaryStar
related: interactingBinaryStar
related: tidalInteraction

rocketBorneInstrument
type: Concept
alt label: rocket borne instrument
definition: rocket-borne instrument
pref label: rocket-borne instrument
related: XRayAstronomy
related: airplaneBorneInstrument
related: balloonBorneInstrument
related: cosmicRayAstronomy
related: gammaRayAstronomy
related: groundBasedAstronomy
related: infraredObservatory
related: satelliteBorneInstrument
related: spaceProbeInstrument
related: spaceTelescope
related: ultravioletAstronomy

roentgenium
type: Concept
alt label: Rg
broader: fundamentalChemicalElement
definition: roentgenium (atomic number 111)
history note: FVH: new (2007-OCT-25)
pref label: roentgenium

RosselandOpacity
type: Concept
broader: opacity
definition: Rosseland opacity
pref label: Rosseland opacity
related: KramersOpacity
related: absorption
related: stellarInterior

rotatingBody
type: Concept
definition: rotating body
narrower: asteroid
narrower: circumstellarDisk
narrower: comet
narrower: dwarfPlanet
narrower: galaxy
narrower: planet
narrower: rotatingStar
pref label: rotating body
related: rigidBodyRotation
related: rotation

rotatingShell
type: Concept
broader: circumstellarShell
definition: rotating shell
pref label: rotating shell

rotatingStar
type: Concept
broader: rotatingBody
definition: rotating star
narrower: periodicVariableStar
pref label: rotating star
related: radiativeBraking
related: synchronousRotation
related: vonZeipelTheorem

rotationalVelocity
type: Concept
broader: velocity
definition: rotational velocity
history note: ES: new (2007-OCT-11)
pref label: rotational velocity
related: rotation
related: tangentialVelocity

rotation
type: Concept
definition: rotation
narrower: EarthRotation
narrower: GalacticRotation
narrower: differentialRotation
narrower: galaxyRotationCurve
narrower: rigidBodyRotation
narrower: synchronousRotation
pref label: rotation
related: angularMomentum
related: angularVelocity
related: equatorialBulge
related: oblateness
related: period
related: rotatingBody
related: rotationalVelocity
scope note: combine with other terms

rProcess
type: Concept
alt label: r process
definition: r-process
pref label: r-process
related: nucleosynthesis
related: pProcess
related: sProcess
related: supernova

RrabStar
type: Concept
broader: RrLyraeStar
definition: RRab star
pref label: RRab star

RraStar
type: Concept
broader: RrLyraeStar
definition: RRa star
pref label: RRa star

RrbStar
type: Concept
broader: RrLyraeStar
definition: RRb star
pref label: RRb star

RrcStar
type: Concept
broader: RrLyraeStar
definition: RRc star
pref label: RRc star

RrLyraeStar
type: Concept
alt label: cluster type variable star
broader: doubleModeVariableStar
broader: populationIiCepheid
broader: pulsatingVariableStar
definition: RR Lyrae star
narrower: BaileyType
narrower: RraStar
narrower: RrabStar
narrower: RrbStar
narrower: RrcStar
pref label: RR Lyrae star
related: BlHerculisStar
related: BlazhkoEffect
related: Cepheid
related: GalacticHalo
related: OosterhoffGroup
related: WVirginisStar
related: globularStarCluster
related: horizontalBranchStar

RrTelescopiiStar
type: Concept
definition: RR Telescopii star
pref label: RR Telescopii star

RsCanumVenaticorumStar
type: Concept
broader: XRaySource
broader: binaryStar
broader: multiPeriodicVariableStar
definition: RS Canum Venaticorum star
pref label: RS Canum Venaticorum star
related: starspot

RStar
type: Concept
broader: giant
broader: lateTypeStar
definition: R star
pref label: R star
related: carbonStar
related: spectralType

rubidium
type: Concept
alt label: Rb
broader: fundamentalChemicalElement
definition: rubidium (atomic number 37)
history note: FVH: new (2007-OCT-25)
pref label: rubidium

runawayStar
type: Concept
definition: runaway star
pref label: runaway star
related: ObStar
related: binaryStar
related: highVelocityStar
related: supernova

ruthenium
type: Concept
alt label: Ru
broader: fundamentalChemicalElement
definition: ruthenium (atomic number 44)
history note: FVH: new (2007-OCT-25)
pref label: ruthenium

rutherfordium
type: Concept
alt label: Rf
broader: fundamentalChemicalElement
definition: rutherfordium (atomic number 104)
history note: FVH: new (2007-OCT-25)
pref label: rutherfordium

RvTauriStar
type: Concept
broader: emissionLineStar
broader: irregularVariableStar
broader: lateTypeSupergiant
broader: longPeriodVariableStar
broader: pulsatingVariableStar
broader: semiRegularVariableStar
definition: RV Tauri star
pref label: RV Tauri star
related: SVulpeculaeStar
related: radialPulsation

RwAurigaeStar
type: Concept
broader: emissionLineStar
broader: irregularVariableStar
broader: preMainSequenceStar
broader: ultravioletExcessStar
definition: RW Aurigae star
pref label: RW Aurigae star
related: HAlphaEmissionLineStar
related: TAssociation
related: TTauriStar

SahaEquation
type: Concept
definition: Saha equation
pref label: Saha equation
related: ion
related: thermalEquilibrium

samarium
type: Concept
alt label: Sm
broader: fundamentalChemicalElement
broader: rareEarth
definition: samarium (atomic number 62)
history note: FVH: new (2007-OCT-25)
pref label: samarium

sampling
type: Concept
definition: sampling
pref label: sampling
scope note: combine with other terms

SarosCycle
type: Concept
definition: Saros cycle
pref label: Saros cycle
related: lunarEclipse
related: lunarPhase
related: metonicCycle

satelliteBorneInstrument
type: Concept
alt label: satellite borne instrument
definition: satellite-borne instrument
pref label: satellite-borne instrument
related: XRayAstronomy
related: airplaneBorneInstrument
related: balloonBorneInstrument
related: cosmicRayAstronomy
related: gammaRayAstronomy
related: groundBasedAstronomy
related: infraredAstronomy
related: millimeterAstronomy
related: rocketBorneInstrument
related: spaceProbeInstrument
related: spaceTelescope
related: ultravioletAstronomy

satelliteLaserRanging
type: Concept
broader: laserRanging
definition: satellite laser ranging
pref label: satellite laser ranging
related: artificialSatellite
related: laser
related: lunarLaserRanging
related: opticalRadar

satellite
type: Concept
definition: satellite
narrower: Moon
narrower: galileanSatellite
narrower: planetSatellite
pref label: satellite
related: SolarSystem
related: globalPositioningSystem
related: planet
related: planetesimal
related: protoplanet
related: rill
related: surfaceOfCelestialBody
related: topography
related: volcano
scope note: natural satellite; see artifical_satellite

Saturn
type: Concept
broader: JovianPlanet
broader: planet
definition: Saturn
history note: FVH: new (2007-SEP-24)
pref label: Saturn
related: SolarSystem

SbfDistance
type: Concept
alt label: SBF
broader: distanceMeasurement
definition: surface brightness fluctuation distance
history note: ES: new (2007-OCT-8)
pref label: SBF distance
related: ellipticalGalaxy

scaleHeight
type: Concept
definition: scale height
pref label: scale height
related: EarthAtmosphere
related: atmosphere
related: atmosphericDensity
related: stellarAtmosphere

scandium
type: Concept
alt label: Sc
broader: fundamentalChemicalElement
broader: rareEarth
definition: scandium (atomic number 21)
history note: FVH: new (2007-OCT-25)
pref label: scandium

scattering
type: Concept
definition: scattering
narrower: ComptonScattering
narrower: MieScattering
narrower: atmosphericExtinction
narrower: elementaryParticleScattering
narrower: gammaRayScattering
narrower: lightScattering
pref label: scattering
related: radiationScattering
related: reflection
related: refraction

SchmidtCamera
type: Concept
broader: camera
broader: photographicInstrument
definition: Schmidt camera
pref label: Schmidt camera
related: SchmidtTelescope
related: correctorPlate

SchmidtTelescope
type: Concept
broader: catadioptricSystem
broader: photographicInstrument
broader: reflectingTelescope
definition: Schmidt telescope
pref label: Schmidt telescope
related: BakerNunnCamera
related: MaksutovTelescope
related: SchmidtCamera
related: correctorPlate
related: objectivePrism
related: wideFieldTelescope

SchwarzschildMetric
type: Concept
definition: Schwarzschild metric
pref label: Schwarzschild metric
related: generalTheoryOfRelativity
related: gravitationalField
related: ionization
related: orbit
related: spaceTimeSingularity

SchwarzschildRadius
type: Concept
definition: Schwarzschild radius
pref label: Schwarzschild radius
related: blackHole
related: generalTheoryOfRelativity
scope note: limiting radius of black hole

scientificField
type: Concept
definition: scientific and related field
narrower: EarthSciences
narrower: aeronomy
narrower: astrobiology
narrower: astrology
narrower: astronomy
narrower: astrophysics
narrower: atomicPhysics
narrower: biology
narrower: celestialMechanics
narrower: chemistry
narrower: engineering
narrower: fluidMechanics
narrower: mathematics
pref label: scientific field

scintillationCounter
type: Concept
broader: counter
definition: scintillation counter
narrower: CerenkovCounter
pref label: scintillation counter
related: imageTube
related: phosphorescence
related: phosphorescentScintillation
related: photomultiplierTube

scintillation
type: Concept
definition: scintillation
narrower: atmosphericScintillation
narrower: interplanetaryScintillation
narrower: interstellarScintillation
narrower: ionosphericScintillation
narrower: phosphorescentScintillation
pref label: scintillation
related: Earth
related: EarthAtmosphere
related: atmosphere
related: atmosphericRefraction
related: speckle
related: turbulenceEarthAtmosphere

SDoradusStar
type: Concept
alt label: P Cygni star
broader: earlyTypeVariableStar
broader: emissionLineStar
broader: shellStar
definition: S Doradus star
pref label: S Doradus star
related: PCygniLineProfile

seaborgium
type: Concept
alt label: Sg
broader: fundamentalChemicalElement
definition: seaborgium (atomic number 106)
history note: FVH: new (2007-OCT-25)
pref label: seaborgium

searchForExtraterrestrialLife
type: Concept
alt label: SETI
change note: FVH: added RT EXTRATERRESTRIAL_INTELLIGENCE (2007-OCT-1)
change note: FVH: explicit wording of token; SETI to ALT (2007-OCT-4)
definition: search for extraterrestrial life
pref label: search for extraterrestrial life
related: extraterrestrialIntelligence
related: extraterrestrialLife

seasonalPhenomena
type: Concept
definition: seasonal phenomena
pref label: seasonal phenomena
scope note: combine with other terms

season
type: Concept
definition: season
pref label: season
scope note: combine with other terms

secondaryCosmicRay
type: Concept
definition: secondary cosmic ray
pref label: secondary cosmic ray
related: cosmicRay
related: cosmicRayShower

secondaryMirror
type: Concept
broader: telescopeMirror
definition: secondary mirror
pref label: secondary mirror
related: CassegrainAntenna
related: CassegrainFocus
related: opticalTelescope
related: primaryMirror
related: reflectingTelescope
related: subreflector
related: tertiaryMirror

secondaryStar
type: Concept
broader: companionStar
definition: secondary star
history note: ES: new (2007-OCT-8)
pref label: secondary star
related: primaryStar
related: tertiaryStar

secularParallax
type: Concept
broader: parallax
definition: secular parallax
pref label: secular parallax
related: movingClusterParallax
related: properMotion
related: starAssociation

seeingMonitor
type: Concept
broader: opticalInstrument
definition: seeing monitor
narrower: differentialImageMotionMonitor
pref label: seeing monitor
related: opticalObservatory
related: seeing
related: siteTesting

seeing
type: Concept
definition: seeing
narrower: domeSeeing
pref label: seeing
related: EarthAtmosphere
related: activeOptics
related: adaptiveOptics
related: atmosphericRefraction
related: atmosphericScintillation
related: pointSpreadFunction
related: seeingMonitor
related: siteTesting
related: speckle
related: speckleInterferometry
related: tipTiltMirror
related: turbulenceEarthAtmosphere

segmentedOptics
type: Concept
definition: segmented optics
pref label: segmented optics
related: adaptiveOptics
related: multipleMirrorTelescope
related: tipTiltMirror
related: veryLargeTelescope

seismology
type: Concept
definition: seismology
narrower: asteroseismology
narrower: helioseismology
pref label: seismology
related: Earth
related: stellarOscillation
related: vibration

selectionEffect
type: Concept
broader: error
definition: selection effect
pref label: selection effect
related: correction
related: statistics
scope note: combine with other terms

selectiveAbsorption
type: Concept
definition: selective absorption
pref label: selective absorption
related: gasToDustRatio
related: interstellarMatter
related: interstellarReddening
related: reddening
related: reddeningLaw

selenium
type: Concept
alt label: Se
broader: fundamentalChemicalElement
definition: selenium (atomic number 34)
history note: FVH: new (2007-OCT-25)
pref label: selenium

selenology
type: Concept
definition: selenology
pref label: selenology
related: Moon

selfAbsorption
type: Concept
alt label: self absorption
definition: self-absorption
pref label: self-absorption
related: spectrum

selfCalibrationMethod
type: Concept
alt label: self calibration method
broader: calibration
definition: self-calibration method
pref label: self-calibration method

semiBariumStar
type: Concept
alt label: semibarium star
broader: bariumStar
definition: semi-barium star
pref label: semi-barium star

semiconductorDevice
type: Concept
definition: semiconductor device
narrower: chargeCoupledDevice
narrower: chargeInjectionDevice
narrower: chargeTransferDevice
narrower: photovoltaicCell
pref label: semiconductor device
related: GunnDiode
related: detector

semiDetachedBinaryStar
type: Concept
alt label: semidetached binary star
broader: binaryStar
broader: closeBinaryStar
definition: semi-detached binary star
pref label: semi-detached binary star
related: detachedBinaryStar

semimajorAxis
type: Concept
alt label: semi-major axis
broader: orbitalElement
definition: semimajor axis
narrower: majorAxis
pref label: semimajor axis
related: binaryStar
related: planet

semiminorAxis
type: Concept
alt label: semi-minor axis
definition: semiminor axis
narrower: minorAxis
pref label: semiminor axis

semiRegularVariableStar
type: Concept
alt label: semiregular variable star
broader: lateTypeGiant
broader: pulsatingVariableStar
broader: variableStar
definition: semi-regular variable star
narrower: RvTauriStar
narrower: SVulpeculaeStar
pref label: semi-regular variable star
related: MiraVariableStar
related: irregularVariableStar
related: supergiant

sensitivity
type: Concept
definition: sensitivity
pref label: sensitivity
related: detector
related: integrationTime
related: limitingMagnitude
related: polarDiagram
related: precision
related: resolution
related: signalDetection
related: signalToNoiseRatio

sensitometer
type: Concept
broader: measuringInstrument
definition: sensitometer
pref label: sensitometer

separation
type: Concept
definition: separation
pref label: separation
related: binaryStar
related: occultingDisk
related: visualBinaryStar
scope note: combine with other terms

sextant
type: Concept
broader: astrometricInstrument
broader: instrument
definition: sextant
pref label: sextant
related: altitudeAngle

SeyfertGalaxy
type: Concept
broader: peculiarGalaxy
definition: Seyfert galaxy
pref label: Seyfert galaxy
related: BlLacertaeObject
related: MarkarianGalaxy
related: SeyfertNucleus
related: XRaySource
related: compactNucleus
related: emissionLineGalaxy
related: linerGalaxy
related: massiveObject

SeyfertNucleus
type: Concept
broader: activeGalacticNucleus
broader: compactNucleus
broader: emissionLineGalaxy
definition: Seyfert nucleus
pref label: Seyfert nucleus
related: SeyfertGalaxy

SGalaxy
type: Concept
broader: spiralGalaxy
definition: spiral galaxy (Yerkes classification scheme)
history note: FVH: new (2007-OCT-12)
pref label: S galaxy
related: YerkesClassification

shadowBand
type: Concept
definition: shadow band
pref label: shadow band
related: diffraction
related: interferenceWave
related: solarEclipse

shapedReflector
type: Concept
definition: shaped reflector
pref label: shaped reflector
related: radioTelescope

shellBurning
type: Concept
definition: shell burning
pref label: shell burning
related: carbonBurning
related: heliumBurning
related: hydrogenBurning
related: nuclearFusion
scope note: nuclear fusion in shell

shell
type: Concept
definition: shell
narrower: circumstellarShell
narrower: convectiveShell
narrower: dustShell
pref label: shell
related: shellStar

shellStar
type: Concept
definition: shell star
narrower: SDoradusStar
narrower: ZAndromedaeStar
narrower: gammaCassiopeiaeStar
pref label: shell star
related: PCygniLineProfile
related: circumstellarShell
related: shell
scope note: ES: deleted BT emission_line_star (2007-OCT-8)

shepherdSatellite
type: Concept
definition: shepherd satellite
pref label: shepherd satellite
related: planetaryRing
related: resonanceGap

shock
type: Concept
definition: shock
pref label: shock
related: collisionalPlasma
related: ionization
related: stellarWind
related: supernova
scope note: combine with other terms

shockWave
type: Concept
definition: shock wave
narrower: bowShock
narrower: ionizingShockWave
pref label: shock wave
related: RankineHugoniotRelation
related: jumpCondition
related: soundSpeed
related: supernovaEnvelope
related: velocityField
related: wavePropagation

shortPeriodVariableStar
type: Concept
definition: short period variable star
narrower: betaCepheiStar
narrower: deltaScutiStar
pref label: short period variable star

shotNoise
type: Concept
broader: noise
definition: shot noise
pref label: shot noise
related: detector
related: electronicEquipment

shutter
type: Concept
definition: shutter
history note: FVH: new (2007-SEP-21)
pref label: shutter
related: camera
related: detector

sidelobe
type: Concept
alt label: lobe [telescope beam]
definition: sidelobe
pref label: sidelobe
related: polarDiagram
related: radioAntenna
related: resolution

siderealTime
type: Concept
alt label: S.T.
broader: time
definition: sidereal time
pref label: sidereal time
related: Earth
related: civilTime
related: equationOfTheEquinox
related: hourAngle
related: transitTime
related: year

siderostat
type: Concept
definition: siderostat
pref label: siderostat
related: altazimuthMounting
related: coelostat
related: drive
related: heliostat
related: telescopeMounting

sigma8
type: Concept
alt label: sigma_8
broader: cosmologicalParameter
definition: the normalization factor of the cosmological matter power spectrum
history note: FVH: new (2007-OCT-24)
pref label: sigma8

signalAnalysis
type: Concept
broader: analysis
definition: signal analysis
pref label: signal analysis
related: signalDetection
related: signalProcessing

signalDetection
type: Concept
broader: detection
definition: signal detection
pref label: signal detection
related: detector
related: limitingMagnitude
related: sensitivity
related: signalAnalysis
related: signalProcessing

signalProcessing
type: Concept
broader: analysis
definition: signal processing
pref label: signal processing
related: signalAnalysis
related: signalDetection

signalToNoiseRatio
type: Concept
alt label: SNR
alt label: signal to noise ratio
definition: signal to noise ratio
pref label: signal-to-noise ratio
related: backgroundNoise
related: integrationTime
related: limitingMagnitude
related: noise
related: sensitivity
related: skyNoise

siliconBurning
type: Concept
broader: nuclearFusion
broader: nucleosynthesis
definition: silicon burning
pref label: silicon burning
related: carbonBurning
related: heliumBurning
related: hydrogenBurning
related: silicon

siliconMonoxide
type: Concept
alt label: SiO
change note: FVH: explicit wording of token (2007-OCT-4)
definition: SiO molecule
history note: FVH: new (2007-OCT-2)
pref label: silicon monoxide
related: SiOMaser
related: silicon

silicon
type: Concept
alt label: Si
broader: fundamentalChemicalElement
definition: silicon (atomic number 14)
history note: FVH: new (2007-OCT-25)
pref label: silicon
related: siliconBurning
related: siliconMonoxide
related: siliconStar

siliconStar
type: Concept
broader: ApStar
broader: metalRichStar
definition: silicon star
pref label: silicon star
related: silicon

silverCoating
type: Concept
broader: coating
broader: thinFilm
definition: silver coating
pref label: silver coating
related: aluminumCoating
related: opticalSurface
related: silver

silver
type: Concept
alt label: Ag
broader: fundamentalChemicalElement
definition: silver (atomic number 47)
history note: FVH: new (2007-OCT-25)
pref label: silver
related: silverCoating

simulation
type: Concept
definition: simulation
narrower: computerSimulation
pref label: simulation
related: model

singularity
type: Concept
definition: singularity
narrower: nakedSingularity
narrower: spaceTimeSingularity
pref label: singularity

SiOMaser
type: Concept
broader: maser
definition: SiO maser
pref label: SiO maser
related: OhMaser
related: interstellarMatter
related: radioSource
related: siliconMonoxide
related: waterMaser

siteProtection
type: Concept
definition: site protection
pref label: site protection
related: airPollution
related: lightPollution
related: observatory

siteTesting
type: Concept
definition: site testing
pref label: site testing
related: observatory
related: pollution
related: seeing
related: seeingMonitor
related: skyBrightness

skyBrightness
type: Concept
definition: sky brightness
narrower: nightSkyBrightness
pref label: sky brightness
related: MilkyWayGalaxy
related: airglow
related: atmosphericRadiation
related: aurora
related: backgroundRadiation
related: siteTesting
related: sunlight
related: twilight
related: zodiacalLight

skyNoise
type: Concept
broader: noise
definition: sky noise
pref label: sky noise
related: backgroundNoise
related: signalToNoiseRatio

sky
type: Concept
definition: sky
pref label: sky
scope note: combine with other terms

skySurvey
type: Concept
broader: survey
definition: sky survey
pref label: sky survey
related: atlas
related: catalog
related: findingChart
related: map

slitMask
type: Concept
broader: spectrographSlit
definition: slit mask
history note: FVH: new (2007-OCT-3)
pref label: slit mask

SloanPhotometry
type: Concept
alt label: SDSS photometry
broader: broadBandPhotometry
broader: photometricSystem
definition: Sloan photometry
history note: FVH: new (2007-SEP-21)
pref label: Sloan photometry
related: twoColorPhotometry

slowNova
type: Concept
alt label: novoid
broader: nova
definition: slow nova
narrower: DqHerculisStar
pref label: slow nova
related: fastNova
related: recurrentNova

SmallMagellanicCloud
type: Concept
alt label: SMC
broader: MagellanicCloud
definition: Small Magellanic Cloud
pref label: Small Magellanic Cloud
related: LargeMagellanicCloud

sodium
type: Concept
alt label: Na
broader: fundamentalChemicalElement
definition: sodium (atomic number 11)
history note: FVH: new (2007-OCT-25)
pref label: sodium

softGammaRayRepeater
type: Concept
broader: gammaRaySource
broader: irregularVariableStar
broader: magnetar
definition: soft gamma-ray repeater
history note: ES: new (2007-OCT-8)
pref label: soft gamma-ray repeater

solarActivity
type: Concept
definition: solar activity
narrower: solarStorm
pref label: solar activity
related: MaunderMinimum
related: activeSun
related: activityIndex
related: aurora
related: butterflyDiagram
related: coronalLoop
related: emergingFlux
related: ephemeralActiveRegion
related: flare
related: heliosphere
related: magneticStorm
related: prominence
related: solarAtmosphere
related: solarCycle
related: solarWind
related: sunspot
related: sunspotCycle
related: sunspotGroup
related: sunspotNumber

solarAtmosphere
type: Concept
broader: stellarAtmosphere
definition: solar atmosphere
pref label: solar atmosphere
related: chromosphere
related: heliopause
related: heliosphere
related: limbDarkening
related: lineFormation
related: solarActivity
related: solarCorona
related: solarPhysics
related: solarStorm
related: solarSurface
related: solarTerrestrialRelation
related: solarWind

solarConstant
type: Concept
definition: solar constant
pref label: solar constant
related: Sun
related: electromagneticRadiation
related: radiation
related: solarPhysics
related: sunlight

solarCorona
type: Concept
broader: corona
definition: solar corona
narrower: mRegion
pref label: solar corona
related: KCorona
related: Sun
related: coronagraph
related: coronalDimming
related: coronalHole
related: coronalLine
related: coronalLoop
related: coronalMassEjection
related: coronalPlume
related: coronalTransient
related: coronalWave
related: solarAtmosphere
related: transitionRegion

solarCycle
type: Concept
definition: solar cycle
pref label: solar cycle
related: activeSun
related: butterflyDiagram
related: quietSun
related: solarActivity
related: solarPhysics
related: sunspotCycle
related: sunspotNumber

solarDay
type: Concept
definition: solar day
pref label: solar day
related: UniversalTime
related: ephemerisTime

solarEclipse
type: Concept
broader: eclipse
definition: solar eclipse
pref label: solar eclipse
related: Moon
related: Sun
related: bailysBead
related: diamondRingEffect
related: flashSpectrum
related: penumbra
related: shadowBand
related: umbra
related: zoneOfTotality

solarFilament
type: Concept
definition: solar filament
pref label: solar filament
related: Sun
related: chromosphere
related: flare
related: prominence
related: sunspot

solarInterior
type: Concept
broader: stellarInterior
definition: solar interior
pref label: solar interior
related: solarNeutrinoProblem
related: solarPhysics
related: stellarEvolution
related: stellarStructure

solarMotion
type: Concept
broader: motion
definition: solar motion
pref label: solar motion
related: antapex
related: apex
scope note: with respect to nearby star

solarNebula
type: Concept
definition: solar nebula
pref label: solar nebula
related: SolarSystem
related: planet
related: protoplanet
related: protoplanetaryNebula

solarNeutrinoProblem
type: Concept
definition: solar neutrino problem
pref label: solar neutrino problem
related: neutrino
related: nuclearReaction
related: solarInterior

solarObservatory
type: Concept
definition: solar observatory
pref label: solar observatory
related: coronagraph
related: solarOpticalTelescope
related: solarRadioTelescope
related: solarTelescope

solarOpticalTelescope
type: Concept
broader: solarTelescope
definition: solar optical telescope
pref label: solar optical telescope
related: solarObservatory
related: solarRadioTelescope

solarOscillation
type: Concept
alt label: five minute oscillation
broader: stellarOscillation
definition: solar oscillation
pref label: solar oscillation
related: asteroseismology
related: helioseismology

solarParallax
type: Concept
definition: solar parallax
pref label: solar parallax
related: AstronomicalUnit
related: EarthOrbit

solarPhysics
type: Concept
definition: solar physics
pref label: solar physics
related: Sun
related: forbushEffect
related: solarAtmosphere
related: solarConstant
related: solarCycle
related: solarInterior
related: solarTelescope
related: solarTerrestrialRelation

solarPlanetaryRelation
type: Concept
alt label: solar planetary relation
definition: solar-planetary relation
narrower: solarTerrestrialRelation
pref label: solar-planetary relation
related: SolarSystem
related: Sun
related: planet

solarRadioTelescope
type: Concept
broader: solarTelescope
definition: solar radio telescope
pref label: solar radio telescope
related: solarObservatory
related: solarOpticalTelescope

solar
type: Concept
definition: solar
pref label: solar
scope note: see under Sun

solarStorm
type: Concept
broader: solarActivity
definition: solar storm
pref label: solar storm
related: solarAtmosphere

solarSurface
type: Concept
definition: solar surface
pref label: solar surface
related: Sun
related: photosphere
related: solarAtmosphere
related: supergranulation

SolarSystem
type: Concept
broader: planetarySystem
definition: Solar System
pref label: Solar System
related: BodesLaw
related: Ceres
related: Earth
related: EarthMoonSystem
related: EdgeworthKuiperBelt
related: Jupiter
related: KreutzSungrazer
related: Mars
related: Mercury
related: Neptune
related: Pluto
related: Saturn
related: Sun
related: Uranus
related: Venus
related: asteroid
related: comet
related: extrasolarPlanet
related: origin
related: planet
related: planetaryAlignment
related: planetaryTheory
related: planetesimal
related: preSolarNebula
related: protoplanet
related: satellite
related: solarNebula
related: solarPlanetaryRelation
related: synodicPeriod
related: transNeptunianObject
related: transplutonianPlanet
scope note: not a complete list of terms

solarTelescope
type: Concept
alt label: tower telescope
broader: telescope
definition: solar telescope
narrower: radioheliograph
narrower: solarOpticalTelescope
narrower: solarRadioTelescope
pref label: solar telescope
related: heliostat
related: solarObservatory
related: solarPhysics

solarTerrestrialRelation
type: Concept
alt label: solar terrestiral relation
broader: solarPlanetaryRelation
definition: solar-terrestrial relation
pref label: solar-terrestrial relation
related: Earth
related: Sun
related: solarAtmosphere
related: solarPhysics

solarWind
type: Concept
broader: interplanetaryMatter
broader: plasma
broader: stellarWind
definition: solar wind
pref label: solar wind
related: PoyntingRobertsonEffect
related: coronalHole
related: heliopause
related: heliosphere
related: interplanetaryGas
related: interstellarWind
related: radiationPressure
related: solarActivity
related: solarAtmosphere

solstice
type: Concept
definition: solstice
narrower: summerSolstice
narrower: winterSolstice
pref label: solstice
related: TropicOfCancer
related: TropicOfCapricorn
related: ecliptic
related: equinox

soundSpeed
type: Concept
alt label: speed of sound
definition: speed of sound
pref label: sound speed
related: acousticWave
related: shockWave

source
type: Concept
definition: astronomical source
history note: FVH: new (2007-NOV-4)
narrower: XRaySource
narrower: compactSource
narrower: cosmicRaySource
narrower: extendedSource
narrower: fieldStar
narrower: gammaRaySource
narrower: gravitationallyLensedSource
narrower: infraredSource
narrower: nonThermalSource
narrower: radioSource
narrower: variableSource
pref label: source

SouthCelestialPole
type: Concept
alt label: S.C.P.
alt label: SCP
broader: celestialPole
definition: South Celestial Pole
pref label: South Celestial Pole
related: NorthCelestialPole

SouthEclipticPole
type: Concept
alt label: S.E.P.
alt label: SEP
broader: eclipticPole
definition: South Ecliptic Pole
pref label: South Ecliptic Pole
related: NorthEclipticPole

southernHemisphere
type: Concept
definition: southern hemisphere
pref label: southern hemisphere
related: northernHemisphere

SouthGalacticPole
type: Concept
alt label: S.G.P.
alt label: SGP
broader: GalacticPole
definition: South Galactic Pole
pref label: South Galactic Pole
related: NorthGalacticPole

spaceAstrometry
type: Concept
broader: astrometry
definition: space astrometry
pref label: space astrometry
related: spaceGeodesy
related: spaceObservatory

spaceAstronomy
type: Concept
broader: astronomy
definition: space astronomy
narrower: XRayAstronomy
narrower: gammaRayAstronomy
narrower: ultravioletAstronomy
pref label: space astronomy
related: artificialSatellite
related: spaceExploration
related: spaceObservatory
related: spaceProbe

spaceBiology
type: Concept
broader: biology
broader: spaceResearch
definition: space biology
pref label: space biology
related: spaceObservatory
related: spaceVehicle

spaceDebris
type: Concept
alt label: debris
broader: spaceVehicle
definition: space debris
pref label: space debris
related: spaceLaw
related: spacePollution

spaceExploration
type: Concept
definition: space exploration
pref label: space exploration
related: discoveries
related: interstellarCommunication
related: planet
related: spaceAstronomy
related: spaceObservatory
related: spaceProbe
related: spaceResearch
related: spaceTelescope
related: spaceVehicle

spaceGeodesy
type: Concept
broader: geodesy
definition: space geodesy
pref label: space geodesy
related: Earth
related: spaceAstrometry
related: spaceObservatory

spaceLaw
type: Concept
definition: space law
pref label: space law
related: spaceDebris
related: spaceResearch

spaceMotion
type: Concept
broader: motion
definition: space motion
narrower: properMotion
narrower: radialVelocity
pref label: space motion
related: GalacticRotation
related: stellarMotion
related: transverseVelocity

spaceObservatory
type: Concept
alt label: orbiting observatory
broader: artificialSatellite
broader: observatory
change note: FVH: merged with orbiting_observatory (2007-NOV-15)
definition: space observatory
narrower: HubbleSpaceTelescope
narrower: IrasSatellite
narrower: XRayObservatory
narrower: gammaRayObservatory
pref label: space observatory
related: XRayAstronomy
related: infraredObservatory
related: spaceAstrometry
related: spaceAstronomy
related: spaceBiology
related: spaceExploration
related: spaceGeodesy
related: spaceProbe
related: spaceResearch
related: spaceTelescope
related: ultravioletAstronomy

spacePollution
type: Concept
broader: pollution
definition: space pollution
pref label: space pollution
related: spaceDebris

spaceProbeInstrument
type: Concept
definition: space probe instrument
narrower: spaceTelescope
pref label: space probe instrument
related: balloonBorneInstrument
related: groundBasedAstronomy
related: rocketBorneInstrument
related: satelliteBorneInstrument
related: spaceProbe

spaceProbe
type: Concept
alt label: probe
definition: space probe
pref label: space probe
related: spaceAstronomy
related: spaceExploration
related: spaceObservatory
related: spaceProbeInstrument
related: spaceVehicle

spaceResearch
type: Concept
alt label: space science
broader: astronomicalResearch
definition: space research
narrower: spaceBiology
pref label: space research
related: spaceExploration
related: spaceLaw
related: spaceObservatory

space
type: Concept
definition: space
pref label: space
related: generalTheoryOfRelativity
related: specialTheoryOfRelativity
related: vacuum

spaceTelescope
type: Concept
broader: spaceProbeInstrument
broader: telescope
definition: space telescope
narrower: XRayTelescope
narrower: gammaRayTelescope
narrower: ultravioletTelescope
pref label: space telescope
related: artificialSatellite
related: balloonBorneInstrument
related: groundBasedAstronomy
related: rocketBorneInstrument
related: satelliteBorneInstrument
related: spaceExploration
related: spaceObservatory
scope note: named telescope not included

spaceTimeCurvature
type: Concept
definition: curvature of space-time
pref label: space-time curvature
related: DarkEnergy
related: cosmology
related: generalTheoryOfRelativity

spaceTimeSingularity
type: Concept
broader: singularity
definition: space-time singularity
pref label: space-time singularity
related: SchwarzschildMetric
related: blackHole
related: nakedSingularity
related: quantumCosmology

spaceVehicle
type: Concept
definition: space vehicle
narrower: spaceDebris
pref label: space vehicle
related: artificialSatellite
related: spaceBiology
related: spaceExploration
related: spaceProbe
scope note: named vehicles not included

specialTheoryOfRelativity
type: Concept
broader: generalTheoryOfRelativity
definition: special theory of relativity
pref label: special theory of relativity
related: space

speckleInterferometry
type: Concept
broader: interferometry
definition: speckle interferometry
pref label: speckle interferometry
related: angularDiameter
related: angularResolution
related: angularSeparation
related: seeing
related: speckle

speckle
type: Concept
definition: speckle
pref label: speckle
related: atmosphericRefraction
related: scintillation
related: seeing
related: speckleInterferometry

spectralBand
type: Concept
definition: spectral band
narrower: molecularBand
pref label: spectral band
related: molecularLine
related: molecularSpectrum
related: telluricLine

spectralClassification
type: Concept
broader: classification
definition: spectral classification
narrower: HenryDraperSystem
narrower: MkClassification
pref label: spectral classification
related: HenryDraperCatalog
related: luminosityClassification
related: spectralType

spectralIndex
type: Concept
definition: spectral index
pref label: spectral index
related: radioFrequency
related: radioSpectrum

spectralLine
type: Concept
alt label: spectrum line
definition: spectral line
narrower: DLine
narrower: FraunhoferLine
narrower: absorptionLine
narrower: calciumLine
narrower: carbonLine
narrower: cyanogenLine
narrower: emissionLine
narrower: hyperfineLine
narrower: metalLine
narrower: molecularLine
narrower: technetiumLine
narrower: telluricLine
narrower: ultravioletLine
pref label: spectral line
related: equivalentWidth
related: fineStructure
related: instrumentalProfile
related: lineBlanketing
related: lineBlending
related: lineBroadening
related: lineFormation
related: lineIdentification
related: lineIntensitite
related: lineProfile
related: lineRatio
related: naturalLineBroadening
related: naturalLineWidth
related: spectralType
related: transitionProbability
scope note: not a complete list of terms

spectralResolution
type: Concept
broader: resolution
definition: spectral resolution
pref label: spectral resolution
related: lineBlending

spectralType
type: Concept
definition: spectral type
pref label: spectral type
related: AStar
related: BStar
related: FStar
related: GStar
related: KStar
related: LDwarf
related: MStar
related: NStar
related: OStar
related: RStar
related: SStar
related: TDwarf
related: lineWidth
related: luminosityClass
related: luminosityClassification
related: spectralClassification
related: spectralLine
related: standardStar
related: temperature
scope note: not a complete list of terms

spectrographSlit
type: Concept
alt label: slit
definition: spectrograph slit
history note: FVH: new (2007-SEP-21)
narrower: longSlit
narrower: slitMask
pref label: spectrograph slit
related: longSlitSpectrum
related: multiSlitSpectrograph
related: spectrograph
related: threeDimensionalSpectrum
related: twoDimensionalSpectrum

spectrograph
type: Concept
broader: instrument
broader: opticalInstrument
broader: telescopeInstrument
change note: FVH: added RT SPECTROGRAPH_SLITS, NT INTEGRAL_FIELD_SPECTROGRAPHS, MULTI_FIBER_SPECTROGRAPHS, and MULTI_SLIT_SPECTROGRAPHS (2007-SEP-21)
definition: spectrograph
narrower: CoudeSpectrograph
narrower: FabryPerotSpectrograph
narrower: FourierSpectrograph
narrower: XRaySpectrograph
narrower: echelleSpectrograph
narrower: gammaRaySpectrograph
narrower: gratingSpectrograph
narrower: grazingIncidenceSpectrograph
narrower: integralFieldSpectrograph
narrower: multiChannelSpectrograph
narrower: multiFiberSpectrograph
narrower: multiSlitSpectrograph
narrower: opticalSpectrograph
narrower: prismSpectrograph
narrower: radioSpectrograph
narrower: ultravioletSpectrograph
pref label: spectrograph
related: VphGrating
related: comparisonLamp
related: diffractionGrating
related: echelleGrating
related: flatFieldLamp
related: grism
related: prism
related: spectrographSlit
related: spectroheliograph
related: spectroscopy

spectrography
type: Concept
alt label: spectrophotography
broader: photography
broader: spectroscopy
definition: spectrography
pref label: spectrography
scope note: see spectroscopy

spectroheliograph
type: Concept
definition: spectroheliograph
pref label: spectroheliograph
related: coronagraph
related: photoheliograph
related: spectrograph

spectrophotometer
type: Concept
broader: photometer
definition: spectrophotometer
pref label: spectrophotometer
related: spectrophotometry
related: telescopeInstrument

spectrophotometry
type: Concept
broader: astronomicalTechnique
broader: observingTechnique
definition: spectrophotometry
pref label: spectrophotometry
related: color
related: opticalScanners
related: photometry
related: spectrophotometer
related: spectroscopy
related: standardCandle

spectroscopicAnalysis
type: Concept
alt label: spectral analysis
definition: spectroscopic analysis
pref label: spectroscopic analysis
related: DopplerEffect
related: MilneEddingtonApproximation
related: absorptionLine
related: collisionBroadening
related: continuousSpectrum
related: emissionLine
related: maximumEntropyMethod
related: spectrum
related: waveMotion
related: waveformAnalysis

spectroscopicBinaryStar
type: Concept
alt label: spectrum binary star
broader: binaryStar
definition: spectroscopic binary star
narrower: twoSpectrumBinaryStar
pref label: spectroscopic binary star
related: DopplerEffect
related: eclipsingBinaryStar
related: ellipsoidalVariableStar
related: mass
related: massFunction
related: velocityCurve

spectroscopy
type: Concept
alt label: spectrometry
broader: astronomicalTechnique
broader: observingTechnique
definition: spectroscopy
narrower: FourierTransformSpectroscopy
narrower: RamanSpectroscopy
narrower: XRaySpectroscopy
narrower: absorptionSpectroscopy
narrower: collisionSpectroscopy
narrower: gammaRaySpectroscopy
narrower: highResolutionSpectrosopy
narrower: interferenceSpectrosocopy
narrower: microwaveSpectroscopy
narrower: opticalSpectroscopy
narrower: spectrography
narrower: threeDimensionalSpectroscopy
narrower: timeResolvedSpectroscopy
narrower: twoDimensionalSpectroscopy
pref label: spectroscopy
related: collisionalExcitation
related: continuousSpectrum
related: heterodyne
related: pressureBroadening
related: radialVelocity
related: reseaux
related: spectrograph
related: spectrophotometry
related: spectrum
scope note: not a complete list of terms

spectrum
type: Concept
definition: spectrum
narrower: abnormalSpectrum
narrower: absorptionSpectrum
narrower: atomicSpectrum
narrower: brillouinSpectrum
narrower: continuousSpectrum
narrower: echelleSpectrum
narrower: emissionSpectrum
narrower: hydrogenSpectrum
narrower: microwaveSpectrum
narrower: molecularSpectrum
narrower: radioSpectrum
narrower: threeDimensionalSpectrum
narrower: twoDimensionalSpectrum
narrower: vibrationalSpectrum
narrower: visibleSpectrum
pref label: spectrum
related: HertzsprungRussellDiagram
related: MkClassification
related: absorptionLine
related: bremsstrahlung
related: contiuum
related: diffractionGrating
related: emissionLine
related: energyLevel
related: equivalentWidth
related: fluorescence
related: forbiddenLine
related: forbiddenTransition
related: freeFreeEmission
related: hyperfineLine
related: prism
related: recombinationLine
related: resonanceLine
related: selfAbsorption
related: spectroscopicAnalysis
related: spectroscopy
related: stimulatedEmission
scope note: not a complete list of terms

spectrumVariableStar
type: Concept
broader: AmStar
broader: ApStar
broader: intrinsicVariableStar
definition: spectrum variable star
narrower: manganeseStar
pref label: spectrum variable star
related: alpha2CanumVenaticorumStar
related: magneticStar
related: obliqueRotator

sphericalAberration
type: Concept
broader: opticalAberration
definition: spherical aberration
pref label: spherical aberration
related: astigmatism
related: chromaticAberration
related: comaticAberration
related: distortion
related: fieldCurvature

sphericalCoordinate
type: Concept
alt label: angular coordinate
definition: spherical coordinate
pref label: spherical coordinate
related: coordinateSystem
related: position
related: referenceSystem

SphSimulation
type: Concept
alt label: SPH
alt label: smoothed-particle hydrodynamics
broader: numericalSimulation
definition: SPH simulation
history note: FVH: new (2007-OCT-3)
pref label: SPH simulation

spicule
type: Concept
definition: spicule
narrower: macroSpicule
pref label: spicule
related: Sun
related: chromosphere

spiralArm
type: Concept
alt label: arm
definition: spiral arm
pref label: spiral arm
related: GalacticStructure
related: galaxyStructure
related: gasDistribution
related: interstellarMagneticField
related: interstellarMatter
related: openStarCluster
related: pitchAngle
related: populationIStar
related: spiralGalaxy

spiralGalaxy
type: Concept
broader: diskGalaxy
broader: galaxy
definition: spiral galaxy
narrower: MilkyWayGalaxy
narrower: SGalaxy
narrower: barredSpiralGalaxy
pref label: spiral galaxy
related: lateTypeGalaxy
related: pitchAngle
related: spiralArm

sProcess
type: Concept
alt label: s process
definition: s-process
pref label: s-process
related: nucleosynthesis
related: pProcess
related: rProcess
related: supernova

SStar
type: Concept
alt label: Se star
broader: giant
broader: lateTypeStar
definition: S star
pref label: S star
related: bariumStar
related: carbonStar
related: heavyMetalStar
related: spectralType
related: technetiumStar
related: zirconiumStar

stability
type: Concept
definition: stability
pref label: stability
related: vibration
scope note: combine with other terms

standardCandle
type: Concept
definition: standard candle
pref label: standard candle
related: effectiveTemperature
related: photometricStandardStar
related: photometry
related: spectrophotometry

standardEpoch
type: Concept
definition: standard epoch
narrower: BesselianEpoch
narrower: JulianEpoch
pref label: standard epoch

standardStar
type: Concept
definition: standard star
narrower: comparisonStar
narrower: photometricStandardStar
pref label: standard star
related: position
related: spectralType

starAssociation
type: Concept
definition: star association
narrower: OAssociation
narrower: ObAssociation
narrower: RAssociation
narrower: TAssociation
pref label: star association
related: GouldsBelt
related: openStarCluster
related: secularParallax

starAtlas
type: Concept
broader: atlas
definition: star atlas
pref label: star atlas
related: findingChart
related: map

starburstGalaxy
type: Concept
broader: galaxy
definition: starburst galaxy
pref label: starburst galaxy
related: starFormation
related: stellarEvolution

starCluster
type: Concept
alt label: cluster of star
broader: cluster
definition: star cluster
narrower: globularStarCluster
narrower: openStarCluster
pref label: star cluster
related: PoincareTheorem
related: clustering
related: initialMassFunction
related: integratedMagnitude
related: luminosityFunction
related: massFunction
related: protocluster
related: relaxationTime
related: tidalDisruption
related: tidalRadius
related: velocityDispersion
related: velocityDistribution
related: virialTheorem

starCount
type: Concept
definition: star count
pref label: star count
related: GalacticStructure
related: massFunction
related: starDistribution
related: statistics

starDistribution
type: Concept
definition: star distribution
pref label: star distribution
related: starCount
related: survey

starFormation
type: Concept
alt label: formation of star
definition: star formation
pref label: star formation
related: BokGlobule
related: JeansLength
related: birthRate
related: cometaryGlobule
related: coolingFlow
related: darkNebula
related: extrasolarPlanet
related: infraredSource
related: preMainSequenceStar
related: protostar
related: starburstGalaxy
related: stellarEvolution
related: stellarRing

StarkBroadening
type: Concept
broader: lineBroadening
definition: Stark broadening
pref label: Stark broadening
related: DopplerBroadening
related: ZeemanSplitting
related: naturalLineWidth

starspot
type: Concept
definition: starspot
narrower: sunspot
pref label: starspot
related: ByDraconisStar
related: RsCanumVenaticorumStar

star
type: Concept
broader: stellarObject
definition: star
narrower: Sun
narrower: activeStar
narrower: bariumStar
narrower: binaryStar
narrower: brightStar
narrower: centralStar
narrower: collapsedStar
narrower: companionStar
narrower: evolvedStar
narrower: faintStar
narrower: fieldStar
narrower: fundamentalStar
narrower: giantBranchStar
narrower: haloStar
narrower: heliumPoorStar
narrower: heliumRichStar
narrower: highLuminosityStar
narrower: highMassStar
narrower: highVelocityStar
narrower: hydrogenDeficientStar
narrower: hypergiant
narrower: intermediatePopulationStar
narrower: lateTypeStar
narrower: lithiumStar
narrower: lowLuminosityStar
narrower: lowMassStar
narrower: mainSequenceStar
narrower: massiveStar
narrower: metalDeficientStar
narrower: metalPoorStar
narrower: metalRichStar
narrower: populationIStar
narrower: populationIiStar
narrower: populationIiiStar
narrower: supernova
narrower: youngStar
pref label: star
scope note: combine star or stellar with other terms

statisticalParallax
type: Concept
broader: parallax
definition: statistical parallax
pref label: statistical parallax

statisticalRelation
type: Concept
definition: statistical relation
narrower: FaberJacksonRelation
narrower: HubbleDiagram
narrower: HubbleLaw
narrower: TullyFisherRelation
narrower: massLuminosityRelation
narrower: massRadiusRelation
narrower: periodAgeRelation
narrower: periodColorRelation
narrower: periodDensityRelation
narrower: periodLuminosityColorRelation
narrower: periodLuminosityRelation
narrower: periodMassRelation
narrower: periodRadiusRelation
narrower: periodSpectrumRelation
narrower: radiusLuminosityRelation
pref label: statistical relation

statistics
type: Concept
definition: statistics
pref label: statistics
related: MonteCarloTechnique
related: distributionFunction
related: radioSourceCount
related: selectionEffect
related: starCount
scope note: combine with other terms

steadyStateTheory
type: Concept
alt label: steady state theory
broader: cosmology
definition: steady-state theory
pref label: steady-state theory
related: BigBangTheory
related: closedUniverse
related: openUniverse

stellarAtmosphere
type: Concept
broader: atmosphere
definition: stellar atmosphere
narrower: solarAtmosphere
pref label: stellar atmosphere
related: chromosphere
related: corona
related: dredgeUp
related: limbBrightening
related: limbDarkening
related: lineBroadening
related: lineFormation
related: lineWidth
related: negativeHIon
related: scaleHeight
related: stellarStructure
related: stellarWind
related: turbulenceStarAtmosphere

stellarBlackHole
type: Concept
broader: blackHole
broader: collapsedStar
broader: stellarObject
definition: stellar black hole
pref label: stellar black hole
related: hypernova
related: stellarEvolution

stellarDynamics
type: Concept
definition: stellar dynamics
pref label: stellar dynamics
related: FokkerPlanckEquation
related: GalacticRotation
related: NBodyProblem
related: PoincareTheorem
related: closeEncounter
related: encounter
related: galaxyRotationCurve
related: properMotion
related: radialVelocity
related: relaxationTime
related: stellarMotion
related: threeBodyProblem
related: twoBodyProblem

stellarEvolution
type: Concept
broader: evolution
change note: FVH: moved STAR_ORIGIN to RT (2007-OCT-1)
definition: stellar evolution
pref label: stellar evolution
related: HenyeyTrack
related: HertzsprungRussellDiagram
related: KerrBlackHole
related: birthRate
related: carbonBurning
related: chemicalEvolution
related: collapsedStar
related: cosmology
related: eProcess
related: evolutionaryTrack
related: funneling
related: giant
related: gravitationalEquilibrium
related: heliumBurning
related: hydrogenBurning
related: initialMassFunction
related: innerCore
related: instabilityStrip
related: luminosityFunction
related: massLoss
related: protostar
related: solarInterior
related: starFormation
related: starburstGalaxy
related: stellarBlackHole
related: stellarInterior

stellarInterior
type: Concept
definition: stellar interior
narrower: solarInterior
pref label: stellar interior
related: ChandrasekharMass
related: ChandrasekharSchoenbergLimit
related: EddingtonLimit
related: RosselandOpacity
related: carbonBurning
related: carbonNitrogenCycle
related: core
related: dredgeUp
related: gravityWave
related: heliumBurning
related: hydrogenBurning
related: innerCore
related: nuclearFusion
related: nucleosynthesis
related: oxygenBurning
related: protonProtonReaction
related: stellarEvolution
related: stellarStructure
related: temperatureZone

stellarMotion
type: Concept
broader: motion
definition: stellar motion
pref label: stellar motion
related: DopplerEffect
related: LocalStandardOfRest
related: astrometry
related: peculiarMotion
related: peculiarVelocity
related: properMotion
related: radialVelocity
related: spaceMotion
related: stellarDynamics

stellarObject
type: Concept
definition: star-like object, including star, brown dwarf, and evolved stellar core (NS, BH, WD)
history note: FVH+ES: new (2007-OCT)
narrower: blackDwarf
narrower: brownDwarf
narrower: neutronStar
narrower: planetar
narrower: star
narrower: stellarBlackHole
narrower: whiteDwarf
pref label: stellar object

stellarOscillation
type: Concept
definition: stellar oscillation
narrower: solarOscillation
pref label: stellar oscillation
related: asteroseismology
related: seismology

stellarPopulation
type: Concept
definition: stellar population
pref label: stellar population
related: diskPopulation
related: haloStar
related: intermediatePopulationStar
related: populationIStar
related: populationIiStar
related: populationIiiStar

stellarRing
type: Concept
broader: ring
definition: stellar ring
pref label: stellar ring
related: starFormation

stellar
type: Concept
definition: stellar
pref label: stellar
scope note: see sn for star

stellarStructure
type: Concept
definition: stellar structure
pref label: stellar structure
related: hydrostaticEquilibrium
related: macroturbulence
related: model
related: polytrope
related: solarInterior
related: stellarAtmosphere
related: stellarInterior

stellarWind
type: Concept
broader: massLoss
broader: plasma
definition: stellar wind
narrower: solarWind
pref label: stellar wind
related: PoyntingRobertsonEffect
related: accretionDisk
related: chromosphere
related: circumstellarShell
related: interstellarWind
related: radiationPressure
related: shock
related: stellarAtmosphere

stimulatedEmission
type: Concept
definition: stimulated emission
pref label: stimulated emission
related: laser
related: maser
related: populationInversion
related: spectrum
related: stimulatedRadiation

stimulatedRadiation
type: Concept
definition: stimulated radiation
pref label: stimulated radiation
related: stimulatedEmission

stokesParameter
type: Concept
definition: Stokes parameter
pref label: stokes parameter
related: lightPolarization
related: polarizedRadiation

stratopause
type: Concept
definition: stratopause
pref label: stratopause
related: EarthAtmosphere
related: mesosphere
related: stratosphere

stratosphere
type: Concept
definition: stratosphere
pref label: stratosphere
related: EarthAtmosphere
related: stratopause
related: tropopause

streakPhotography
type: Concept
broader: photography
definition: streak photography
pref label: streak photography

streamer
type: Concept
definition: streamer
pref label: streamer
related: comet
related: tail

stroboscope
type: Concept
broader: instrument
definition: stroboscope
pref label: stroboscope

StromgrenPhotometry
type: Concept
alt label: Stromgren uvby system
alt label: four-color photometry
alt label: uvby system
broader: mediumBandPhotometry
broader: photometricSystem
definition: Stromgren photometry
pref label: Stromgren photometry
related: HBetaPhotometry
related: KapteynSelectedArea
related: eRegion
related: fRegion

StromgrenSphere
type: Concept
broader: gaseousSphere
definition: Stromgren sphere
pref label: Stromgren sphere
related: interstellarMatter
related: ionization
related: ionizedGas

strongGravitationalLensing
type: Concept
broader: gravitationalLensing
definition: strong gravitational lensing (resolved)
history note: FVH: new (2007-OCT-8)
pref label: strong gravitational lensing

strongInteraction
type: Concept
broader: interaction
definition: strong interaction
pref label: strong interaction
related: nuclearPhysics
related: weakInteraction
scope note: between atomic particle

strontiumStar
type: Concept
definition: strontium star
pref label: strontium star
related: magneticStar
related: strontium

strontium
type: Concept
alt label: Sr
broader: fundamentalChemicalElement
definition: strontium (atomic number 38)
history note: FVH: new (2007-OCT-25)
pref label: strontium
related: strontiumStar

structure
type: Concept
definition: structure
narrower: galaxyStructure
pref label: structure
related: planet
scope note: combine with other terms

subdwarf
type: Concept
broader: subluminousStar
definition: subdwarf star
narrower: ASubdwarf
narrower: BSubdwarf
narrower: FSubdwarf
narrower: GSubdwarf
narrower: KSubdwarf
narrower: LSubdwarf
narrower: MSubdwarf
narrower: OSubdwarf
narrower: TSubdwarf
narrower: lateTypeSubdwarf
pref label: subdwarf
related: HarmanSeatonSequence
related: dwarf

subgiant
type: Concept
broader: postMainSequenceStar
definition: subgiant star
narrower: ASubgiant
narrower: FSubgiant
narrower: GSubgiant
narrower: KSubgiant
narrower: MSubgiant
pref label: subgiant
related: luminosityClassification

subluminousStar
type: Concept
definition: subluminous star
narrower: degenerateStar
narrower: subdwarf
pref label: subluminous star
related: populationIiStar

submillimeterAstronomy
type: Concept
broader: radioAstronomy
definition: submillimeter astronomy
pref label: submillimeter astronomy
related: millimeterAstronomy
related: radioObservatory
related: submillimeterRadiation

submillimeterRadiation
type: Concept
alt label: submillimeter wave
broader: electromagneticRadiation
change note: FVH: moved submillimeter_wave to here, cleaned up (2007-OCT-8)
definition: submillimeter radiation
pref label: submillimeter radiation
related: submillimeterAstronomy

subreflector
type: Concept
definition: subreflector
pref label: subreflector
related: CassegrainAntenna
related: CassegrainFocus
related: radioTelescope
related: secondaryMirror
related: tertiaryMirror

sulfur
type: Concept
alt label: S
alt label: sulphur
broader: fundamentalChemicalElement
definition: sulfur (atomic number 16)
history note: FVH: new (2007-OCT-25)
pref label: sulfur

summerSolstice
type: Concept
broader: solstice
definition: summer solstice
pref label: summer solstice
related: TropicOfCancer
related: winterSolstice

Sun
type: Concept
broader: star
definition: Sun
narrower: activeSun
pref label: Sun
related: FraunhoferLine
related: HanleEffect
related: LocalStandardOfRest
related: SolarSystem
related: activeProminence
related: activeRegion
related: bailysBead
related: brightPoint
related: chromosphere
related: diamondRingEffect
related: flare
related: granulation
related: granule
related: lunarEclipse
related: macroSpicule
related: mottle
related: photosphere
related: prominence
related: quiescentProminence
related: solarConstant
related: solarCorona
related: solarEclipse
related: solarFilament
related: solarPhysics
related: solarPlanetaryRelation
related: solarSurface
related: solarTerrestrialRelation
related: spicule
scope note: combine Sun or solar with other terms; not a complete list of terms

sunlight
type: Concept
definition: sunlight
pref label: sunlight
related: skyBrightness
related: solarConstant
related: twilight

sunspotCycle
type: Concept
definition: sunspot cycle
pref label: sunspot cycle
related: MaunderMinimum
related: butterflyDiagram
related: solarActivity
related: solarCycle
related: sunspot

sunspotGroup
type: Concept
definition: sunspot group
narrower: bipolarGroup
pref label: sunspot group
related: solarActivity
related: sunspotNumber

sunspotNumber
type: Concept
alt label: Wolf number
alt label: relative sunspot number
definition: sunspot number
pref label: sunspot number
related: MaunderMinimum
related: butterflyDiagram
related: solarActivity
related: solarCycle
related: sunspotGroup

sunspot
type: Concept
alt label: sun spot
broader: starspot
change note: FVH: added ALT sun_spot, BT starspot (2007-OCT-8)
definition: sunspot
pref label: sunspot
related: EvershedEffect
related: WilsonEffect
related: activeSun
related: bipolarGroup
related: butterflyDiagram
related: emergingFlux
related: magneticField
related: magneticStorm
related: penumbra
related: plage
related: prominence
related: solarActivity
related: solarFilament
related: sunspotCycle
related: umbra

SunyaevZeldovichEffect
type: Concept
alt label: Sunyaev Zeldovich effect
definition: Sunyaev-Zeldovich effect
pref label: Sunyaev-Zeldovich effect
related: XRayEmission
related: backgroundRadiation
related: galaxyCluster
related: intraclusterMatter
related: microwaveBackground

supercluster
type: Concept
definition: supercluster
pref label: supercluster
related: galaxyCluster

superconductingTunnelJunction
type: Concept
broader: detector
definition: super-conducting tunnel junction detector
history note: FVH: new (2007-SEP-21)
pref label: superconducting tunnel junction
related: quantumMechanics

supergalacticCoordinateSystem
type: Concept
broader: celestialCoordinateSystem
definition: supergalactic coordinate system
history note: ES: new (2007-OCT-8)
pref label: supergalactic coordinate system
related: galaxyCluster
related: supergalacticLatitude
related: supergalacticLongitude

supergalacticLatitude
type: Concept
broader: latitude
definition: supergalactic latitude
history note: ES: (2007-OCT-8)
pref label: supergalactic latitude
related: supergalacticCoordinateSystem
related: supergalacticLongitude

supergalacticLongitude
type: Concept
broader: longitude
definition: supergalactic longitude
history note: ES: (2007-OCT-8)
pref label: supergalactic longitude
related: supergalacticCoordinateSystem
related: supergalacticLatitude

supergiant
type: Concept
broader: highLuminosityStar
broader: postMainSequenceStar
definition: supergiant star
narrower: ASupergiant
narrower: BSupergiant
narrower: FSupergiant
narrower: GSupergiant
narrower: KSupergiant
narrower: OSupergiant
narrower: earlyTypeSupergiant
narrower: lateTypeSupergiant
pref label: supergiant
related: HubbleSandageVariableStar
related: LcVariableStar
related: RCoronaeBorealisStar
related: hypergiant
related: irregularVariableStar
related: semiRegularVariableStar
related: supermassiveStar

supergranulation
type: Concept
broader: granulation
definition: supergranulation
pref label: supergranulation
related: solarSurface

superhump
type: Concept
broader: variability
definition: superhump
pref label: superhump
related: SuUrsaeMajorisStar
related: accretionDisk
related: precession

supermassiveStar
type: Concept
definition: supermassive star
pref label: supermassive star
related: massiveStar
related: supergiant

supernovaEnvelope
type: Concept
definition: supernova envelope
pref label: supernova envelope
related: shockWave
related: supernova

supernovaRemnant
type: Concept
alt label: SNR
definition: supernova remnant
pref label: supernova remnant
related: XRaySource
related: blackHole
related: neutronStar
related: pulsar
related: radioSource
related: whiteDwarf
related: whiteHole

supernova
type: Concept
alt label: SN
broader: highLuminosityStar
broader: star
change note: FVH: moved presupernovas from UF to RT (2007-SEP-21)
definition: supernova
narrower: TypeIaSupernova
narrower: TypeIbSupernova
narrower: TypeIcSupernova
narrower: TypeIiSupernova
narrower: hypernova
pref label: supernova
related: OpikTheory
related: cataclysmicVariableStar
related: eProcess
related: frozenInElement
related: gravitationalCollapse
related: massLoss
related: neutrino
related: nova
related: nuclearFusion
related: nucleosynthesis
related: opticalOutburst
related: pProcess
related: preSupernova
related: progenitor
related: pulsar
related: rProcess
related: runawayStar
related: sProcess
related: shock
related: supernovaEnvelope
related: supportSystem

supportSystem
type: Concept
definition: support system
pref label: support system
related: instrument
related: supernova
related: telescope
scope note: combine with other terms

surfaceBrightness
type: Concept
broader: brightness
definition: surface brightness
pref label: surface brightness
related: LGalaxy
related: gravityDarkening
related: photosphere
related: surfacePhotometry
related: temperature
related: vonZeipelTheorem

surfaceGravity
type: Concept
alt label: acceleration of gravity
definition: surface gravity
pref label: surface gravity
related: diameter
related: gravitationalForce
related: gravityDarkening
related: lineWidth
related: luminosity
related: luminosityClassification
related: mass

surfaceOfCelestialBody
type: Concept
alt label: surface celestial body
definition: surface [celestial body]
narrower: canyon
pref label: surface of celestial body
related: Moon
related: dustStorm
related: geology
related: lunarDome
related: maria
related: petrology
related: photosphere
related: planet
related: satellite
related: topography
related: volatile
related: volcano
related: waterIce

surfacePhotometry
type: Concept
alt label: area photometry
broader: photometry
definition: surface photometry
pref label: surface photometry
related: driftScan
related: galaxy
related: isophot
related: isophotalDiameter
related: nebula
related: surfaceBrightness

surfaceProperty
type: Concept
broader: property
definition: surface property
pref label: surface property
related: albedo
scope note: combine with other terms

survey
type: Concept
definition: survey
narrower: XRaySurvey
narrower: skySurvey
narrower: ultravioletSurvey
pref label: survey
related: atlas
related: catalog
related: radioSourceCount
related: starDistribution

SuUrsaeMajorisStar
type: Concept
broader: dwarfNova
definition: SU Ursae Majoris star
pref label: SU Ursae Majoris star
related: WzSagittaeStar
related: superhump

SVulpeculaeStar
type: Concept
broader: longPeriodVariableStar
broader: pulsatingVariableStar
broader: semiRegularVariableStar
definition: S Vulpeculae star
pref label: S Vulpeculae star
related: MiraVariableStar
related: RvTauriStar

SwanBand
type: Concept
broader: molecularBand
definition: Swan band
pref label: Swan band
related: carbonMonoxide
related: molecularSpectrum

SxArietisStar
type: Concept
alt label: helium variable star
broader: cataclysmicVariableStar
broader: dwarfNova
broader: earlyTypeVariableStar
broader: eruptiveBinaryStar
broader: magneticVariableStar
change note: FVH: deleted wrong referernces to CV's (2007-OCT-2)
definition: SX Arietis star
pref label: SX Arietis star
related: alpha2CanumVenaticorumStar

SxPhoenicisStar
type: Concept
broader: multiPeriodicVariableStar
broader: populationIiStar
broader: pulsatingVariableStar
definition: SX Phoenicis star
pref label: SX Phoenicis star

symbioticNova
type: Concept
broader: nova
broader: symbioticStar
definition: symbiotic nova
pref label: symbiotic nova

symbioticStar
type: Concept
broader: emissionLineStar
broader: eruptiveBinaryStar
definition: symbiotic star
narrower: ZAndromedaeStar
narrower: symbioticNova
pref label: symbiotic star
related: PCygniLineProfile
related: XRayBinaryStar
related: cataclysmicVariableStar
related: dustShell

symbol
type: Concept
definition: symbol
pref label: symbol
related: unit

synchronousDetector
type: Concept
broader: detector
definition: synchronous detector
pref label: synchronous detector

synchronousRotation
type: Concept
broader: rotation
definition: synchronous rotation
pref label: synchronous rotation
related: closeBinaryStar
related: orbit
related: rotatingStar

synchrotronRadiation
type: Concept
broader: electromagneticRadiation
broader: radiation
definition: synchrotron radiation
narrower: cyclotronRadiation
narrower: gyrosynchrotronRadiation
pref label: synchrotron radiation
related: RazinEffect
related: bremsstrahlung
related: magnetohydrodynamics
related: nonThermalSource
related: radiationMechanism
related: relativisticElectron

synodicPeriod
type: Concept
definition: synodic period
pref label: synodic period
related: SolarSystem
related: conjunction
related: opposition
related: planet
related: syzygy

system
type: Concept
definition: system
narrower: absorptionLineSystem
pref label: system
scope note: combine with other terms

syzygy
type: Concept
definition: syzygy
pref label: syzygy
related: conjunction
related: opposition
related: planet
related: synodicPeriod
scope note: conjunction or opposition of planet

tail
type: Concept
definition: tail
pref label: tail
related: comet
related: headTailGalaxy
related: interactingGalaxy
related: streamer

tangentialVelocity
type: Concept
broader: velocity
definition: tangential velocity
pref label: tangential velocity
related: orbitalVelocity
related: radialVelocity
related: rotationalVelocity

tantalum
type: Concept
alt label: Ta
broader: fundamentalChemicalElement
definition: tantalum (atomic number 73)
history note: FVH: new (2007-OCT-25)
pref label: tantalum

tArray
type: Concept
broader: array
broader: radioInterferometer
definition: t array
pref label: t array
related: yArray

TAssociation
type: Concept
alt label: T-association
broader: starAssociation
definition: T association
pref label: T association
related: FuOrionisStar
related: HAlphaEmissionLineStar
related: HerbigHaroObject
related: RwAurigaeStar
related: TTauriStar
related: flareStar
related: flashStar
related: irregularVariableStar
related: preMainSequenceStar
related: youngStar
related: youngStarCluster

taxonomy
type: Concept
definition: taxonomy
pref label: taxonomy
related: classification

TDwarf
type: Concept
broader: brownDwarf
definition: T dwarf
history note: FVH: new (2007-OCT-2)
pref label: T dwarf
related: TSubdwarf
related: lowMassStar
related: spectralType

teachingInAstronomy
type: Concept
alt label: education
definition: teaching in astronomy
pref label: teaching in astronomy

technetiumLine
type: Concept
broader: metalLine
broader: spectralLine
definition: technetium line
pref label: technetium line
related: technetium

technetiumStar
type: Concept
definition: technetium star
pref label: technetium star
related: NStar
related: SStar
related: technetium

technetium
type: Concept
alt label: Tc
broader: fundamentalChemicalElement
definition: technetium (atomic number 43)
history note: FVH: new (2007-OCT-25)
pref label: technetium
related: technetiumLine
related: technetiumStar

tektite
type: Concept
broader: meteorite
definition: tektite
narrower: australite
narrower: bediasite
narrower: indochinite
narrower: moldavite
pref label: tektite

telescopeArray
type: Concept
broader: array
definition: telescope array
pref label: telescope array
related: fillingFactor
related: interferometer
related: telescope

telescopeConstruction
type: Concept
definition: telescope construction
pref label: telescope construction
related: telescope

telescopeDesign
type: Concept
definition: telescope design
pref label: telescope design
related: telescope
related: telescopeMounting

telescopeInstrument
type: Concept
alt label: telescope instrumentation
broader: instrument
definition: telescope instrument
narrower: photometer
narrower: polarimeter
narrower: spectrograph
pref label: telescope instrument
related: controlSystem
related: detector
related: feed
related: feedHorn
related: remoteControlSystem
related: spectrophotometer
related: telescope
scope note: not a complete list of terms

telescopeMirror
type: Concept
broader: mirror
definition: telescope mirror
narrower: primaryMirror
narrower: secondaryMirror
narrower: tertiaryMirror
pref label: telescope mirror
related: telescope

telescopeMounting
type: Concept
definition: telescope mounting
narrower: altazimuthMounting
narrower: equatorialMounting
pref label: telescope mounting
related: coelostat
related: heliostat
related: polarAxis
related: siderostat
related: telescope
related: telescopeDesign

telescope
type: Concept
broader: opticalInstrument
definition: telescope
narrower: CassegrainTelescope
narrower: GregorianTelescope
narrower: automatedTelescope
narrower: gammaRayTelescope
narrower: grazingIncidenceTelescope
narrower: infraredTelescope
narrower: opticalTelescope
narrower: radioTelescope
narrower: solarTelescope
narrower: spaceTelescope
pref label: telescope
related: antenna
related: controlSystem
related: dome
related: drive
related: focus
related: guideSystem
related: observatory
related: opticalAberration
related: pointingAccuracy
related: pointingError
related: remoteControlSystem
related: supportSystem
related: telescopeArray
related: telescopeConstruction
related: telescopeDesign
related: telescopeInstrument
related: telescopeMirror
related: telescopeMounting
related: vignetting
scope note: only the broad classes are shown below; specific type will be found under these, or from the hierarchical list

televisionCamera
type: Concept
alt label: TV camera
definition: television camera
pref label: television camera
related: television
related: televisionDetector
related: twoDimensionalDetector

televisionDetector
type: Concept
alt label: TV camera
alt label: television camera tube
broader: multiChannelDetector
broader: photoelectronicDevice
broader: twoDimensionalDetector
definition: television detector
pref label: television detector
related: CcdDetector
related: television
related: televisionCamera

television
type: Concept
alt label: TV
definition: television
pref label: television
related: televisionCamera
related: televisionDetector

telluricLine
type: Concept
broader: spectralLine
definition: telluric line
pref label: telluric line
related: EarthAtmosphere
related: spectralBand
scope note: from Earth's atmosphere

tellurium
type: Concept
alt label: Te
broader: fundamentalChemicalElement
definition: tellurium (atomic number 52)
history note: FVH: new (2007-OCT-25)
pref label: tellurium

temperatureControl
type: Concept
definition: temperature control
pref label: temperature control
related: airConditioning
related: cryogenics
related: cryostat
related: dome
related: temperatureDistribution
related: ventilation

temperatureDistribution
type: Concept
definition: temperature distribution
pref label: temperature distribution
related: temperatureControl
related: temperatureZone

temperatureEffect
type: Concept
alt label: thermal effect
definition: temperature effect
pref label: temperature effect
scope note: combine with other terms

temperatureFluctuation
type: Concept
definition: temperature fluctuation
pref label: temperature fluctuation
scope note: combine with other terms

temperatureScale
type: Concept
definition: temperature scale
narrower: absoluteTemperatureScale
narrower: celsiusTemperatureScale
pref label: temperature scale
related: Kelvin

temperature
type: Concept
definition: temperature
narrower: brightnessTemperature
narrower: effectiveTemperature
narrower: electronTemperature
narrower: ionTemperature
pref label: temperature
related: absoluteTemperatureScale
related: celsiusTemperatureScale
related: color
related: emissivity
related: limbBrightening
related: limbDarkening
related: radiativeEquilibrium
related: spectralType
related: surfaceBrightness
related: thermalConductivity
related: thermodynamics
scope note: combine with other terms

temperatureZone
type: Concept
definition: temperature zone
pref label: temperature zone
related: atmosphere
related: stellarInterior
related: temperatureDistribution

terbium
type: Concept
alt label: Tb
broader: fundamentalChemicalElement
broader: rareEarth
definition: terbium (atomic number 65)
history note: FVH: new (2007-OCT-25)
pref label: terbium

terminatorLine
type: Concept
definition: terminator line
pref label: terminator line
related: lunarPhase

terrestrialRadiation
type: Concept
broader: atmosphericRadiation
definition: terrestrial radiation
pref label: terrestrial radiation
related: greenhouseEffect
related: infraredRadiation
scope note: ES: moved atmospheric_radiation from NT to BT (2007-OCT-8)

tertiaryMirror
type: Concept
broader: telescopeMirror
definition: tertiary mirror
history note: FVH: new (2007-SEP-21)
pref label: tertiary mirror
related: NasmythFocus
related: opticalTelescope
related: primaryMirror
related: reflectingTelescope
related: secondaryMirror
related: subreflector

tertiaryStar
type: Concept
broader: companionStar
definition: tertiary star
history note: ES: new (2007-OCT-8)
pref label: tertiary star
related: primaryStar
related: secondaryStar

testing
type: Concept
definition: testing
pref label: testing
scope note: combine with other terms

thallium
type: Concept
alt label: Tl
broader: fundamentalChemicalElement
definition: thallium (atomic number 81)
history note: FVH: new (2007-OCT-25)
pref label: thallium

theoreticalAstrophysics
type: Concept
broader: astrophysics
change note: FVH: moved ASTROPHYSICS to BT (2007-OCT-1)
definition: theoretical astrophysics
pref label: theoretical astrophysics

theory
type: Concept
definition: theory
pref label: theory
related: research
scope note: combine with other terms

thermalConductivity
type: Concept
definition: thermal conductivity
pref label: thermal conductivity
related: conduction
related: temperature

thermalEmission
type: Concept
broader: emissionSpectrum
definition: thermal emission
pref label: thermal emission
related: freeFreeEmission
related: infraredEmission

thermalEquilibrium
type: Concept
definition: thermal equilibrium
pref label: thermal equilibrium
related: SahaEquation
related: localThermodynamicEquilibrium
related: thermalInstability
related: thermodynamicEquilibrium
related: thermodynamics

thermalHistory
type: Concept
definition: thermal history
pref label: thermal history
scope note: combine with other terms

thermalInstability
type: Concept
definition: thermal instability
pref label: thermal instability
related: convection
related: localThermodynamicEquilibrium
related: thermalEquilibrium
related: thermodynamicEquilibrium
related: turbulenceEarthAtmosphere
related: turbulenceStarAtmosphere

thermalProperty
type: Concept
broader: property
definition: thermal property
pref label: thermal property
scope note: combine with other terms

thermalRadiation
type: Concept
broader: electromagneticRadiation
broader: radiation
definition: thermal radiation
pref label: thermal radiation
related: JohnsonNoise
related: blackBodyRadiation
related: infraredRadiation

thermalStability
type: Concept
definition: thermal stability
pref label: thermal stability
related: RayleighNumber
related: localThermodynamicEquilibrium
related: thermodynamicEquilibrium

thermalStructure
type: Concept
definition: thermal structure
pref label: thermal structure
related: convection
related: turbulenceEarthAtmosphere
related: turbulenceStarAtmosphere
scope note: combine with other terms

thermionicEmission
type: Concept
alt label: dark current
definition: thermionic emission
pref label: thermionic emission
related: cathode
related: electron
related: ion

thermodynamicEquilibrium
type: Concept
definition: thermodynamic equilibrium
narrower: localThermodynamicEquilibrium
pref label: thermodynamic equilibrium
related: energyTransfer
related: thermalEquilibrium
related: thermalInstability
related: thermalStability
related: thermodynamics

thermodynamics
type: Concept
definition: thermodynamics
pref label: thermodynamics
related: adiabaticProcess
related: energyTransfer
related: enthalpy
related: entropy
related: localThermodynamicEquilibrium
related: plasma
related: temperature
related: thermalEquilibrium
related: thermodynamicEquilibrium

thermoluminescence
type: Concept
broader: luminescence
definition: thermoluminescence
pref label: thermoluminescence

thermonuclearReaction
type: Concept
definition: thermonuclear reaction
pref label: thermonuclear reaction
scope note: see nuclear fusion

thermosphere
type: Concept
definition: thermosphere
pref label: thermosphere
related: EarthAtmosphere
related: exosphere
related: ionosphere
related: mesopause
related: upperAtmosphere

thickness
type: Concept
definition: thickness
pref label: thickness
scope note: combine with other terms

thinFilm
type: Concept
broader: opticalFilm
definition: thin film
narrower: aluminumCoating
narrower: antireflectionCoating
narrower: silverCoating
pref label: thin film
related: coating
related: mirror
related: opticalSurface
related: reflection
related: vacuumTechnique
related: vaporDeposition

ThomsonScattering
type: Concept
broader: ComptonScattering
broader: lightScattering
broader: radiationScattering
definition: Thomson scattering
pref label: Thomson scattering
related: RayleighScattering

thorium
type: Concept
alt label: Th
broader: fundamentalChemicalElement
definition: thorium (atomic number 90)
history note: FVH: new (2007-OCT-25)
pref label: thorium

threeBodyProblem
type: Concept
alt label: three body problem
definition: three-body problem
pref label: three-body problem
related: NBodyProblem
related: celestialMechanics
related: orbit
related: perturbation
related: stellarDynamics
related: twoBodyProblem

threeDimensionalSpectroscopy
type: Concept
alt label: three dimensional spectroscopy
broader: spectroscopy
definition: three-dimensional spectroscopy
pref label: three-dimensional spectroscopy
related: threeDimensionalSpectrum

threeDimensionalSpectrum
type: Concept
alt label: three dimensional spectrum
broader: spectrum
definition: three-dimensional spectrum
history note: FVH: new (2007-SEP-21)
pref label: three-dimensional spectrum
related: extendedObject
related: integralFieldSpectrograph
related: longSlitSpectrum
related: multiFiberSpectrograph
related: multiSlitSpectrograph
related: spectrographSlit
related: threeDimensionalSpectroscopy
related: twoDimensionalSpectroscopy

thulium
type: Concept
alt label: Tm
broader: fundamentalChemicalElement
broader: rareEarth
definition: thulium (atomic number 69)
history note: FVH: new (2007-OCT-25)
pref label: thulium

tidalDisruption
type: Concept
definition: tidal disruption
pref label: tidal disruption
related: RocheLimit
related: differentialRotation
related: starCluster
related: tidalDistortion
related: tidalFriction
related: tidalInteraction
related: tidalRadius

tidalDistortion
type: Concept
definition: tidal distortion
pref label: tidal distortion
related: differentialRotation
related: interactingGalaxy
related: tidalDisruption
related: tidalFriction
related: tidalInteraction

tidalFriction
type: Concept
definition: tidal friction
pref label: tidal friction
related: EarthMoonSystem
related: closeBinaryStar
related: interactingBinaryStar
related: interactingGalaxy
related: tidalDisruption
related: tidalDistortion
related: tidalInteraction
related: tide

tidalInteraction
type: Concept
definition: tidal interaction
pref label: tidal interaction
related: RocheLobe
related: interactingBinaryStar
related: interactingGalaxy
related: tidalDisruption
related: tidalDistortion
related: tidalFriction

tidalRadius
type: Concept
definition: tidal radius
pref label: tidal radius
related: starCluster
related: tidalDisruption

tide
type: Concept
definition: tide
narrower: atmosphericTide
narrower: oceanTide
narrower: polarTide
pref label: tide
related: tidalFriction

timeMeasurement
type: Concept
alt label: time determination
definition: time measurement
pref label: time measurement
related: time

timeResolvedSpectroscopy
type: Concept
broader: spectroscopy
definition: time-resolved spectroscopy
pref label: time-resolved spectroscopy
related: highSpeedPhotometer
related: variableStar

timeSignal
type: Concept
definition: time signal
pref label: time signal
related: globalPositioningSystem
related: timeStandard
related: timeSynchronization

timeStandard
type: Concept
definition: time standard
pref label: time standard
related: atomicClock
related: clock
related: globalPositioningSystem
related: timeSignal
related: timeSynchronization

timeSynchronization
type: Concept
alt label: time synchronisation UK
definition: time synchronization
pref label: time synchronization
related: atomicClock
related: globalPositioningSystem
related: radioInterferometry
related: timeSignal
related: timeStandard
related: veryLongBaselineInterferometry

time
type: Concept
definition: time
narrower: UniversalTime
narrower: civilTime
narrower: dynamicalTime
narrower: ephemerisTime
narrower: meanSolarTime
narrower: siderealTime
pref label: time
related: BesselianEpoch
related: EarthOrbit
related: EarthRotation
related: GregorianCalendar
related: JulianDate
related: JulianEpoch
related: astrometricInstrument
related: atomicClock
related: calendar
related: chronometer
related: clock
related: ephemeris
related: epoch
related: generalTheoryOfRelativity
related: timeMeasurement
related: transitInstrument
related: transitTime
related: year

timingEquipment
type: Concept
alt label: timing device
definition: timing equipment
narrower: clock
narrower: pendulum
pref label: timing equipment

tin
type: Concept
alt label: Sn
broader: fundamentalChemicalElement
definition: tin (atomic number 50)
history note: FVH: new (2007-OCT-25)
pref label: tin

tipTiltMirror
type: Concept
alt label: tip tilt mirror
definition: tip-tilt mirror
pref label: tip-tilt mirror
related: activeOptics
related: seeing
related: segmentedOptics

titaniumOxide
type: Concept
alt label: TiO
definition: TiO molecule
history note: FVH: new (2007-OCT-2)
pref label: titanium oxide
related: LDwarf
related: MStar
related: oxygen
related: titanium

titanium
type: Concept
alt label: Ti
broader: fundamentalChemicalElement
definition: titanium (atomic number 22)
history note: FVH: new (2007-OCT-25)
pref label: titanium
related: titaniumOxide

topography
type: Concept
definition: topography
pref label: topography
related: Earth
related: planet
related: satellite
related: surfaceOfCelestialBody
scope note: combine with other terms

torus
type: Concept
definition: torus
pref label: torus
related: circumstellarDisk
related: interstellarMatter

totalEclipse
type: Concept
broader: eclipse
definition: total eclipse
pref label: total eclipse
related: annularEclipse
related: eclipsingBinaryStar
related: partialEclipse
related: umbra

traceElement
type: Concept
broader: chemicalElement
definition: trace element
pref label: trace element
related: metalAbundance

tracking
type: Concept
definition: tracking
pref label: tracking
related: autoguider
related: controlSystem
related: pointingAccuracy
related: pointingError

trajectory
type: Concept
definition: trajectory
pref label: trajectory
related: orbit

transferFunction
type: Concept
definition: transfer function
narrower: modulationTransferFunction
narrower: opticalTransferFunction
narrower: pointSpreadFunction
pref label: transfer function

transitCircle
type: Concept
broader: transitInstrument
definition: transit circle
pref label: transit circle
related: transitTelescope

transitInstrument
type: Concept
broader: astrometricInstrument
definition: transit instrument
narrower: meridianCircle
narrower: transitCircle
narrower: transitTelescope
pref label: transit instrument
related: astrometry
related: meridianObservation
related: time
related: transit

transitionProbability
type: Concept
definition: transition probability
pref label: transition probability
related: gValue
related: gfValue
related: lineFormation
related: lineWidth
related: oscillatorStrength
related: spectralLine

transitionRegion
type: Concept
definition: transition region
pref label: transition region
related: chromosphere
related: solarCorona

transitTelescope
type: Concept
broader: transitInstrument
definition: transit telescope
narrower: zenithTelescope
pref label: transit telescope
related: meridianObservation
related: transitCircle
related: transitTime

transitTime
type: Concept
definition: transit time
pref label: transit time
related: RightAscension
related: hourAngle
related: meridianObservation
related: siderealTime
related: time
related: transitTelescope

transit
type: Concept
definition: transit
pref label: transit
related: astrometry
related: eclipse
related: occultation
related: transitInstrument

transmissionGrating
type: Concept
broader: diffractionGrating
definition: transmission grating
narrower: objectiveGrating
pref label: transmission grating
related: VphGrating
related: echelleGrating
related: grism
related: reflectionGrating

transmission
type: Concept
definition: transmission
pref label: transmission
related: absorption
related: optics
related: reflection
related: refraction
related: transparency
scope note: combine with other terms

transNeptunianObject
type: Concept
alt label: TNO
definition: trans-Neptunian object
history note: FVH: new (2007-OCT-2)
narrower: EdgeworthKuiperBeltObject
pref label: trans-Neptunian object
related: EdgeworthKuiperBelt
related: OortCloud
related: SolarSystem
related: asteroid

transparency
type: Concept
definition: transparency
pref label: transparency
related: absorptionCoefficient
related: atmosphericWindow
related: opacity
related: transmission

transplutonianPlanet
type: Concept
definition: transplutonian planet
pref label: transplutonian planet
related: SolarSystem

transportProcess
type: Concept
definition: transport process
pref label: transport process
related: radiativeTransfer

transverseVelocity
type: Concept
broader: velocity
definition: transverse velocity
pref label: transverse velocity
related: properMotion
related: radialVelocity
related: spaceMotion

trigonometricParallax
type: Concept
broader: parallax
definition: trigonometric parallax
pref label: trigonometric parallax
related: AstronomicalUnit
related: distance
related: nearbyStar

tripleStar
type: Concept
broader: multipleStar
change note: FVH: moved MULTIPLE_STARS to BT (2007-OCT-1)
definition: triple star
pref label: triple star

tritium
type: Concept
broader: hydrogen
definition: tritium, an isotope of hydrogen
pref label: tritium
related: isotope

TrojanGroup
type: Concept
broader: minorPlanetFamily
definition: Trojan group
pref label: Trojan group
related: AmorGroup
related: ApolloGroup

tropicalYear
type: Concept
broader: year
definition: tropical year
pref label: tropical year
related: EarthOrbit

TropicOfCancer
type: Concept
definition: Tropic of Cancer
pref label: Tropic of Cancer
related: TropicOfCapricorn
related: solstice
related: summerSolstice

TropicOfCapricorn
type: Concept
definition: Tropic of Capricorn
pref label: Tropic of Capricorn
related: TropicOfCancer
related: solstice
related: winterSolstice

tropopause
type: Concept
definition: tropopause
pref label: tropopause
related: EarthAtmosphere
related: stratosphere
related: troposphere

troposphere
type: Concept
definition: troposphere
pref label: troposphere
related: Earth
related: EarthAtmosphere
related: exosphere
related: tropopause

trueAnomaly
type: Concept
broader: orbitalAnomaly
change note: FVH: moved ANOMALY to BT (2007-OCT-1)
definition: true anomaly
pref label: true anomaly

truePosition
type: Concept
broader: position
definition: true position
pref label: true position
related: apparentPosition
related: astrometry
related: coordinateSystem

TSubdwarf
type: Concept
broader: brownDwarf
broader: subdwarf
definition: T subdwarf
history note: FVH: new (2007-OCT-9)
pref label: T subdwarf
related: TDwarf

TTauriStar
type: Concept
alt label: TTS
alt label: YY Orionis star
broader: emissionLineStar
broader: irregularVariableStar
broader: preMainSequenceStar
change note: FVH: moved yy_orinois_star to ALT, added NT CLASSICAL_T_TAURI_STARS and WEAK_LINE_T_TAURI_STARS (2007-SEP-24)
definition: T Tauri star
narrower: FuOrionisStar
narrower: classicalTTauriStar
narrower: weakLineTTauriStar
pref label: T Tauri star
related: HerbigHaroObject
related: RwAurigaeStar
related: TAssociation
related: emissionNebula
related: protostar

TullyFisherRelation
type: Concept
broader: statisticalRelation
definition: Tully-Fisher relation
pref label: Tully-Fisher relation
related: cosmology
related: galaxy
related: lineWidth
related: redshift

tungsten
type: Concept
alt label: W
broader: fundamentalChemicalElement
definition: tungsten (atomic number 74)
history note: FVH: new (2007-OCT-25)
pref label: tungsten

turbidity
type: Concept
definition: turbidity
pref label: turbidity
related: halation
related: photographicEmulsion

turbulenceEarthAtmosphere
type: Concept
definition: turbulence [Earth atmosphere]
narrower: macroturbulence
narrower: microturbulence
pref label: turbulence Earth atmosphere
related: EarthAtmosphere
related: convection
related: pointSpreadFunction
related: scintillation
related: seeing
related: thermalInstability
related: thermalStructure
scope note: in Earth's atmosphere

turbulenceStarAtmosphere
type: Concept
definition: turbulence [star atmosphere]
narrower: macroturbulence
narrower: microturbulence
pref label: turbulence star atmosphere
related: convection
related: lineBroadening
related: stellarAtmosphere
related: thermalInstability
related: thermalStructure
scope note: in stellar atmosphere or in interstellar matter

turnoffPoint
type: Concept
definition: turnoff point
pref label: turnoff point
related: HertzsprungRussellDiagram
related: age
related: giantBranch
related: globularStarCluster
related: mainSequence
related: openStarCluster

twilight
type: Concept
definition: twilight
pref label: twilight
related: EarthAtmosphere
related: skyBrightness
related: sunlight

twoBodyProblem
type: Concept
alt label: two body problem
definition: two-body problem
pref label: two-body problem
related: EarthMoonSystem
related: NBodyProblem
related: binaryStar
related: celestialMechanics
related: planet
related: stellarDynamics
related: threeBodyProblem

twoColorDiagram
type: Concept
alt label: two color diagram
definition: two-color diagram
pref label: two-color diagram
related: colorIndex
related: photometry

twoColorPhotometry
type: Concept
alt label: two color photometry
broader: broadBandPhotometry
definition: two-color photometry
narrower: BvPhotometry
pref label: two-color photometry
related: JohnsonPhotometry
related: SloanPhotometry

twoDimensionalDetector
type: Concept
alt label: two dimensional detector
broader: detector
definition: two-dimensional detector
narrower: CcdDetector
narrower: imageTube
narrower: televisionDetector
pref label: two-dimensional detector
related: chargeCoupledDevice
related: chargeInjectionDevice
related: chargeTransferDevice
related: flatField
related: imageProcessing
related: pixel
related: televisionCamera

twoDimensionalSpectroscopy
type: Concept
alt label: two dimensional spectroscopy
broader: spectroscopy
definition: two-dimensional spectroscopy
pref label: two-dimensional spectroscopy
related: threeDimensionalSpectrum
related: twoDimensionalSpectrum

twoDimensionalSpectrum
type: Concept
alt label: two dimensional spectrum
broader: spectrum
definition: two-dimensional spectrum
pref label: two-dimensional spectrum
related: extendedObject
related: longSlitSpectrum
related: spectrographSlit
related: twoDimensionalSpectroscopy
scope note: FVH: added RT SPECTROGRAPH_SLITS (2007-SEP-21)

twoSpectrumBinaryStar
type: Concept
alt label: spectrum binary star
alt label: two spectrum binary star
broader: spectroscopicBinaryStar
definition: two-spectrum binary star
pref label: two-spectrum binary star

TypeIaSupernova
type: Concept
broader: supernova
definition: Type Ia supernova
history note: FVH: new (2007-OCT-1)
pref label: Type Ia supernova
related: TypeIbSupernova
related: TypeIcSupernova
related: TypeIiSupernova
related: cosmology

TypeIbSupernova
type: Concept
broader: supernova
definition: Type Ib supernova
history note: FVH: new (2007-OCT-1)
pref label: Type Ib supernova
related: TypeIaSupernova
related: TypeIcSupernova
related: TypeIiSupernova

TypeIcSupernova
type: Concept
broader: supernova
definition: Type Ic supernova
history note: FVH: new (2007-OCT-1)
pref label: Type Ic supernova
related: TypeIaSupernova
related: TypeIbSupernova
related: TypeIiSupernova

TypeIiSupernova
type: Concept
broader: supernova
definition: Type II supernova
history note: FVH: new (2007-OCT-1)
pref label: Type II supernova
related: TypeIaSupernova
related: TypeIbSupernova
related: TypeIcSupernova

UGeminorumStar
type: Concept
alt label: SS Cygni star
broader: dwarfNova
change note: FVH: update (2007-SEP-24)
definition: U Geminorum star
pref label: U Geminorum star
related: UvPerseiStar
related: emissionLineStar

ultravioletAstronomy
type: Concept
alt label: UV astronomy
broader: spaceAstronomy
definition: ultraviolet astronomy
pref label: ultraviolet astronomy
related: balloonBorneInstrument
related: rocketBorneInstrument
related: satelliteBorneInstrument
related: spaceObservatory
related: ultravioletTelescope

ultravioletBackground
type: Concept
broader: backgroundRadiation
broader: ultravioletRadiation
definition: ultraviolet background
pref label: ultraviolet background
related: XRayBackground
related: gammaRayBackground
related: microwaveBackground
related: radioBackground

ultravioletCamera
type: Concept
broader: camera
definition: ultraviolet camera
pref label: ultraviolet camera

ultravioletColor
type: Concept
definition: ultraviolet color
pref label: ultraviolet color
related: ultravioletPhotometry

ultravioletContinuum
type: Concept
broader: continuumRadiation
broader: ultravioletRadiation
definition: ultraviolet continuum
pref label: ultraviolet continuum

ultravioletDetector
type: Concept
broader: detector
definition: ultraviolet detector
pref label: ultraviolet detector
related: photometer

ultravioletExcessStar
type: Concept
alt label: UV excess star
definition: ultraviolet excess star
narrower: RwAurigaeStar
pref label: ultraviolet excess star
related: metalDeficientStar
related: metalPoorStar

ultravioletExtinction
type: Concept
definition: ultraviolet extinction
pref label: ultraviolet extinction
related: atmosphericExtinction
scope note: in Earth's atmosphere

ultravioletFilter
type: Concept
definition: ultraviolet filter
pref label: ultraviolet filter
related: interferenceFilter
related: opticalFilter

ultravioletLine
type: Concept
broader: spectralLine
definition: ultraviolet line
pref label: ultraviolet line
related: lineSpectrum

ultravioletLuminosity
type: Concept
broader: luminosity
definition: ultraviolet luminosity
pref label: ultraviolet luminosity

ultravioletObservatory
type: Concept
broader: observatory
definition: ultraviolet observatory
history note: FVH: new (2007-NOV-1)
narrower: HubbleSpaceTelescope
pref label: ultraviolet observatory
related: ultravioletRadiation

ultravioletPhotography
type: Concept
broader: photography
definition: ultraviolet photography
pref label: ultraviolet photography
related: camera

ultravioletPhotometry
type: Concept
broader: broadBandPhotometry
broader: mediumBandPhotometry
broader: photometry
definition: ultraviolet photometry
pref label: ultraviolet photometry
related: UMagnitude
related: ultravioletColor
related: ultravioletRadiation

ultravioletRadiation
type: Concept
alt label: ultraviolet_light
broader: electromagneticRadiation
broader: radiation
change note: FVH: change BT electromagnetic_wave to BT electromagnetic_radiation (2007-OCT-8)
definition: ultraviolet radiation
narrower: extremeUltravioletRadiation
narrower: farUltravioletRadiation
narrower: nearUltravioletRadiation
narrower: ultravioletBackground
narrower: ultravioletContinuum
pref label: ultraviolet radiation
related: CerenkovRadiation
related: LymanContinuum
related: LymanSeries
related: blackBodyRadiation
related: lineBlanketing
related: ultravioletObservatory
related: ultravioletPhotometry
related: ultravioletSpectrograph

ultravioletSource
type: Concept
alt label: ultraviolet object
definition: ultraviolet source
narrower: earlyTypeStar
pref label: ultraviolet source

ultravioletSpectrograph
type: Concept
broader: spectrograph
definition: ultraviolet spectrograph
pref label: ultraviolet spectrograph
related: ultravioletRadiation

ultravioletSurvey
type: Concept
broader: survey
definition: ultraviolet survey
pref label: ultraviolet survey
related: catalog

ultravioletTelescope
type: Concept
broader: spaceTelescope
definition: ultraviolet telescope
pref label: ultraviolet telescope
related: ultravioletAstronomy

ultraviolet
type: Concept
alt label: UV
definition: ultraviolet
pref label: ultraviolet
scope note: combine with other terms

UMagnitude
type: Concept
broader: apparentMagnitude
definition: U magnitude
pref label: U magnitude
related: BesselPhotometry
related: JohnsonPhotometry
related: ultravioletPhotometry

umbra
type: Concept
definition: umbra
pref label: umbra
related: WilsonEffect
related: eclipse
related: lunarEclipse
related: penumbra
related: solarEclipse
related: sunspot
related: totalEclipse
related: zoneOfTotality

underabundance
type: Concept
broader: abundance
definition: underabundance
history note: ES: new (2007-OCT-8)
pref label: underabundance
related: overabundance

unit
type: Concept
definition: unit
pref label: unit
related: metrology
related: symbol
scope note: of measurement

UniversalTime
type: Concept
alt label: U.T.
alt label: UT
broader: time
definition: universal time
narrower: Ut1
narrower: coordinatedUniversalTime
pref label: Universal Time
related: civilTime
related: ephemerisTime
related: meanSolarTime
related: solarDay
related: year

universe
type: Concept
alt label: cosmos
definition: universe
pref label: universe
related: DarkEnergy
related: cosmogony
related: cosmology
related: largeScaleStructure
related: metagalaxy
scope note: see also under cosmology

unsharpMasking
type: Concept
definition: unsharp masking
pref label: unsharp masking
related: photographicProcessing
related: photography

upperAtmosphere
type: Concept
definition: upper atmosphere
pref label: upper atmosphere
related: EarthAtmosphere
related: aurora
related: exosphere
related: ionosphere
related: magnetosphere
related: mesosphere
related: thermosphere
related: vanAllenRadiationBelt
scope note: Earth's atmosphere

upsilonSagittariiStar
type: Concept
broader: eclipsingBinaryStar
definition: upsilon Sagittarii star
pref label: upsilon Sagittarii star

uranium
type: Concept
alt label: U
broader: fundamentalChemicalElement
definition: uranium (atomic number 92)
history note: FVH: new (2007-OCT-25)
pref label: uranium

Uranus
type: Concept
broader: JovianPlanet
broader: planet
definition: Uranus
history note: FVH: new (2007-SEP-24)
pref label: Uranus
related: SolarSystem

urcaProcess
type: Concept
broader: nuclearReaction
definition: urca process
pref label: urca process

Ut1
type: Concept
broader: UniversalTime
definition: UT1
history note: FVH: new (2007-OCT-3)
pref label: UT1
related: coordinatedUniversalTime

UuHerculisStar
type: Concept
broader: FSupergiant
broader: irregularVariableStar
broader: postAsymptoticGiantBranch
change note: FVH: corrected content (2007-OCT-5)
definition: UU Herculis star
pref label: UU Herculis star

UvCetiStar
type: Concept
broader: flareStar
broader: variableSource
definition: UV Ceti star
pref label: UV Ceti star
related: flashStar

UvPerseiStar
type: Concept
broader: cataclysmicVariableStar
definition: UV Persei star
pref label: UV Persei star
related: UGeminorumStar
related: dwarfNova

UxUrsaeMajorisStar
type: Concept
broader: novaLikeVariable
definition: UX Ursae Majoris-like star
pref label: UX Ursae Majoris star
related: AmCanumVenaticorumStar
related: ZCamelopardalisStar
related: dwarfNova

vacuumTechnique
type: Concept
definition: vacuum technique
pref label: vacuum technique
related: aluminizing
related: aluminumCoating
related: outgassing
related: thinFilm
related: vaporDeposition

vacuum
type: Concept
definition: vacuum
pref label: vacuum
related: pressure
related: space

vanadium
type: Concept
alt label: V
broader: fundamentalChemicalElement
definition: vanadium (atomic number 23)
history note: FVH: new (2007-OCT-25)
pref label: vanadium

vanAllenRadiationBelt
type: Concept
broader: radiationBelt
definition: van Allen belt
definition: van Allen radiation belt
pref label: van Allen radiation belt
related: magnetohydrodynamics
related: upperAtmosphere

vaporDeposition
type: Concept
definition: vapor deposition
pref label: vapor deposition
related: aluminumCoating
related: coating
related: thinFilm
related: vacuumTechnique

variability
type: Concept
definition: variability
narrower: superhump
pref label: variability
related: highState
related: lowState
scope note: combine with other terms

variableSource
type: Concept
broader: radioSource
broader: source
definition: variable source
narrower: BlLacertaeObject
narrower: UvCetiStar
narrower: activeGalacticNucleus
pref label: variable source
related: highState
related: lowState
related: quasar

variableStar
type: Concept
definition: variable star
narrower: cataclysmicVariableStar
narrower: eclipsingBinaryStar
narrower: ellipsoidalVariableStar
narrower: intrinsicVariableStar
narrower: irregularVariableStar
narrower: peculiarVariableStar
narrower: pulsatingVariableStar
narrower: semiRegularVariableStar
pref label: variable star
related: HAlphaEmissionLineStar
related: HeIiIonizationZone
related: OhIrStar
related: PurkinjeEffect
related: amplitude
related: comparisonStar
related: fundamentalFrequency
related: highSpeedPhotometer
related: lightCurve
related: maximum
related: minimum
related: period
related: periodDetermination
related: phaseShift
related: phaseWave
related: timeResolvedSpectroscopy
related: velocityCurve
related: visualObservation
scope note: only the broad classes are shown below; specific type will be found under these, or from the hierarchical list

velocityCurve
type: Concept
definition: velocity curve
pref label: velocity curve
related: lightCurve
related: maximum
related: minimum
related: period
related: phaseShift
related: phaseWave
related: spectroscopicBinaryStar
related: variableStar
related: velocity

velocityDispersion
type: Concept
definition: velocity dispersion
pref label: velocity dispersion
related: galaxyCluster
related: luminosityDispersionRelation
related: missingMass
related: starCluster
related: virialTheorem

velocityDistribution
type: Concept
definition: velocity distribution
pref label: velocity distribution
related: galaxyCluster
related: starCluster
related: velocity
related: virialTheorem

velocityEllipsoid
type: Concept
definition: velocity ellipsoid
pref label: velocity ellipsoid
related: velocity

velocityField
type: Concept
definition: velocity field
pref label: velocity field
related: galaxy
related: shockWave
related: velocity
scope note: combine with other terms

velocityOfLight
type: Concept
alt label: speed of light
broader: physicalConstant
broader: velocity
definition: velocity of light
pref label: velocity of light
related: apparentSuperluminalMotion
related: ergosphere
related: eventHorizon
related: lightCone
related: lightYear

velocitySpace
type: Concept
definition: velocity space
pref label: velocity space
related: phaseSpace
related: velocity

velocity
type: Concept
definition: velocity
narrower: angularVelocity
narrower: escapeVelocity
narrower: heliocentricVelocity
narrower: orbitalVelocity
narrower: parabolicVelocity
narrower: peculiarVelocity
narrower: radialVelocity
narrower: relativisticVelocity
narrower: rotationalVelocity
narrower: tangentialVelocity
narrower: transverseVelocity
narrower: velocityOfLight
pref label: velocity
related: highVelocityCloud
related: highVelocityStar
related: kinematics
related: momentum
related: velocityCurve
related: velocityDistribution
related: velocityEllipsoid
related: velocityField
related: velocitySpace
scope note: ES: added rotational_velocity (2007-OCT-11)
scope note: combine with other terms

ventilation
type: Concept
definition: ventilation
pref label: ventilation
related: airConditioning
related: dome
related: domeSeeing
related: temperatureControl
scope note: combine with other terms

Venus
type: Concept
broader: planet
definition: Venus
pref label: Venus
related: SolarSystem
related: ashenLight

vernalEquinox
type: Concept
broader: equinox
definition: vernal equinox
pref label: vernal equinox
related: autumnalEquinox

verticalCircle
type: Concept
definition: vertical circle
pref label: vertical circle
related: altazimuthMounting
related: meridianCircle

VeryLargeArray
type: Concept
alt label: VLA
broader: veryLongBaselineInterferometer
definition: Very Large Array
pref label: Very Large Array

veryLargeTelescope
type: Concept
broader: opticalTelescope
definition: very large telescope
pref label: very large telescope
related: multipleMirrorTelescope
related: segmentedOptics

veryLongBaselineInterferometer
type: Concept
alt label: VLBI
broader: array
broader: interferometer
broader: radioInterferometer
broader: radioTelescope
definition: very long baseline interferometer
narrower: VeryLargeArray
pref label: very long baseline interferometer
related: longBaselineInterferometer

veryLongBaselineInterferometry
type: Concept
alt label: VLBI
broader: interferometry
broader: radioInterferometry
definition: very long baseline interferometry
pref label: very long baseline interferometry
related: atomicClock
related: longBaselineInterferometry
related: radioAstrometry
related: timeSynchronization

vibrationalSpectrum
type: Concept
broader: spectrum
definition: vibrational spectrum
pref label: vibrational spectrum
related: molecularSpectrum
related: qBranch

vibration
type: Concept
definition: vibration
pref label: vibration
related: amplitude
related: antinode
related: node
related: seismology
related: stability

vignetting
type: Concept
definition: vignetting
pref label: vignetting
related: fieldOfView
related: telescope
related: wideFieldTelescope

VilniusPhotometry
type: Concept
broader: mediumBandPhotometry
definition: Vilnius photometry
pref label: Vilnius photometry
related: GenevaPhotometry

virialTheorem
type: Concept
definition: virial theorem
pref label: virial theorem
related: galaxyCluster
related: gravitation
related: radialVelocity
related: starCluster
related: velocityDispersion
related: velocityDistribution

virtualObservatory
type: Concept
definition: virtual observatory
history note: FVH: new (2007-SEP-24)
pref label: virtual observatory
related: dataCenter
related: dataRetrieval
related: database

viscosity
type: Concept
definition: viscosity
pref label: viscosity
related: plasma

visibilityFunction
type: Concept
definition: visibility function
pref label: visibility function
related: apertureSynthesis
related: interferenceFringe
related: interferometry

visibleRadiation
type: Concept
alt label: light
broader: electromagneticRadiation
change note: FVH: combined with light (2007-OCT-8)
definition: visible radiation
narrower: polarizedLight
pref label: visible radiation
related: color
related: darkness
related: gravitationalLensing
related: lightAbsorption
related: lightInterference
related: lightScattering
related: luminescence
related: refraction
related: visibleSpectrum

visibleSpectrum
type: Concept
broader: spectrum
definition: visible spectrum
pref label: visible spectrum
related: continuousSpectrum
related: visibleRadiation

vision
type: Concept
definition: vision
narrower: colorVision
pref label: vision
related: darkAdaption
related: image
related: visualAcuity

visualAcuity
type: Concept
definition: visual acuity
pref label: visual acuity
related: resolution
related: vision

visualBinaryStar
type: Concept
broader: binaryStar
broader: wideBinaryStar
definition: visual binary star
pref label: visual binary star
related: occultingDisk
related: orbitalMotion
related: separation
related: visualObservation
scope note: see also optical double star

visualMagnitude
type: Concept
definition: visual magnitude
pref label: visual magnitude
related: PurkinjeEffect
related: VMagnitude
related: photovisualMagnitude

visualObservation
type: Concept
definition: visual observation
pref label: visual observation
related: PurkinjeEffect
related: variableStar
related: visualBinaryStar

VMagnitude
type: Concept
broader: apparentMagnitude
definition: V magnitude
pref label: V magnitude
related: BesselPhotometry
related: JohnsonPhotometry
related: photovisualMagnitude
related: visualMagnitude

VoigtProfile
type: Concept
definition: Voigt profile
pref label: Voigt profile
related: absorptionLine
related: lineSpectrum

volatile
type: Concept
definition: volatile
pref label: volatile
related: planet
related: surfaceOfCelestialBody

volcano
type: Concept
definition: volcano
pref label: volcano
related: crater
related: planet
related: satellite
related: surfaceOfCelestialBody

vonZeipelTheorem
type: Concept
definition: von Zeipel theorem
pref label: von Zeipel theorem
related: binaryStar
related: gravity
related: gravityDarkening
related: rotatingStar
related: surfaceBrightness

VphGrating
type: Concept
broader: diffractionGrating
definition: VPH grating
history note: FVH: new (2007-SEP-21)
pref label: VPH grating
related: spectrograph
related: transmissionGrating

VySculpturisStar
type: Concept
broader: novaLikeVariable
definition: VY Sculpturis star
pref label: VY Sculpturis star
related: ZCamelopardalisStar

WalravenPhotometry
type: Concept
alt label: VBLUW photometry
broader: mediumBandPhotometry
broader: photometricSystem
definition: Walraven photometry
pref label: Walraven photometry

waterIce
type: Concept
alt label: ice
definition: water ice
pref label: water ice
related: planet
related: surfaceOfCelestialBody
related: water

waterMaser
type: Concept
broader: maser
definition: water maser
pref label: water maser
related: OhMaser
related: SiOMaser
related: water

waterVapor
type: Concept
definition: water vapor
pref label: water vapor
related: atmosphere
related: planet
related: water

water
type: Concept
broader: interstellarMolecule
definition: water
pref label: water
related: waterIce
related: waterMaser
related: waterVapor

waveformAnalysis
type: Concept
definition: waveform analysis
pref label: waveform analysis
related: FourierAnalysis
related: periodDetermination
related: spectroscopicAnalysis

waveguide
type: Concept
definition: waveguide
narrower: opticalWaveguide
narrower: radioWaveguide
pref label: waveguide

wavelength
type: Concept
definition: wavelength
pref label: wavelength
related: acousticWave
related: electromagneticRadiation
related: frequency
scope note: combine with other terms

waveMotion
type: Concept
broader: motion
definition: wave motion
pref label: wave motion
related: interferenceWave
related: spectroscopicAnalysis
related: wavePropagation

wavePropagation
type: Concept
definition: wave propagation
pref label: wave propagation
related: refraction
related: shockWave
related: wave
related: waveMotion

wave
type: Concept
definition: wave
narrower: acousticWave
narrower: driftWave
narrower: electromagneticRadiation
narrower: gravitationalWave
narrower: gravityWave
pref label: wave
related: oscillation
related: wavePropagation

WcnStar
type: Concept
broader: WolfRayetStar
change note: FVH: moved WOLF_RAYET_STARS to BT (2007-OCT-1)
definition: WCN star
pref label: WCN star

WcStar
type: Concept
broader: WolfRayetStar
change note: FVH: moved WOLF_RAYET_STARS to BT (2007-OCT-1)
definition: WC star
pref label: WC star

weakGBandStar
type: Concept
broader: giant
broader: metalPoorStar
definition: weak G band star
pref label: weak G band star

weakGravitationalLensing
type: Concept
broader: gravitationalLensing
definition: weak gravitational lensing (resolved)
history note: FVH: new (2007-OCT-8)
pref label: weak gravitational lensing

weakInteraction
type: Concept
broader: interaction
definition: weak interaction
narrower: FermiInteraction
pref label: weak interaction
related: nuclearPhysics
related: strongInteraction
scope note: between atomic particles

weakLineTTauriStar
type: Concept
alt label: WTTS
broader: TTauriStar
definition: weak-line T Tauri star
history note: FVH: new (2007-SEP-24)
pref label: weak-line T Tauri star

weatherStation
type: Concept
broader: measuringInstrument
definition: weather station
history note: FVH: new (2007-SEP-21)
pref label: weather station
related: altimeter
related: anemometer
related: barometer
related: windVane

webcam
type: Concept
broader: camera
definition: webcam
history note: FVH: new (2007-SEP-21)
pref label: webcam

whiteDwarf
type: Concept
broader: compactObject
broader: degenerateDwarf
broader: evolvedStar
broader: stellarObject
change note: FVH: moved DA_star to NT, added DB_STARS (2007-OCT-1)
definition: white dwarf star
narrower: DaStar
narrower: DbStar
narrower: DoStar
narrower: ZzCetiStar
pref label: white dwarf
related: ChandrasekharMass
related: XRayPulsar
related: blackDwarf
related: cataclysmicVariableStar
related: collapsedStar
related: supernovaRemnant

whiteHole
type: Concept
definition: white hole
pref label: white hole
related: blackHole
related: cosmology
related: gravitationalLensing
related: nakedSingularity
related: supernovaRemnant

wideAngleLens
type: Concept
alt label: wide angle lens
definition: wide-angle lens
pref label: wide-angle lens
related: allSkyCamera
related: allSkyPhotography
related: camera

wideBinaryStar
type: Concept
broader: binaryStar
change note: FVH: moved BINARY_STARS to BT and VISUAL_BINARY_STARS to NT (2007-OCT-1)
definition: wide binary star
narrower: visualBinaryStar
pref label: wide binary star

wideFieldTelescope
type: Concept
alt label: wide field telescope
broader: reflectingTelescope
definition: wide-field telescope
narrower: BakerNunnCamera
narrower: allSkyCamera
pref label: wide-field telescope
related: BouwersTelescope
related: MaksutovTelescope
related: SchmidtTelescope
related: vignetting

WilsonBappuEffect
type: Concept
alt label: Wilson Bappu effect
definition: Wilson-Bappu effect
pref label: Wilson-Bappu effect
related: CaIiEmissionLine
related: KLine
related: absoluteMagnitude
related: lateTypeStar

WilsonEffect
type: Concept
definition: Wilson effect
pref label: Wilson effect
related: penumbra
related: sunspot
related: umbra

window
type: Concept
definition: window
narrower: GalacticWindow
narrower: atmosphericWindow
pref label: window
related: interstellarAbsorption
scope note: combine with other terms

windVane
type: Concept
broader: measuringInstrument
definition: wind vane
history note: FVH: new (2007-SEP-21)
pref label: wind vane
related: anemometer
related: weatherStation

winterSolstice
type: Concept
broader: solstice
definition: winter solstice
pref label: winter solstice
related: TropicOfCapricorn
related: summerSolstice

WnStar
type: Concept
broader: WolfRayetStar
change note: FVH: moved WOLF_RAYET_STARS to BT (2007-OCT-1)
definition: WN star
pref label: WN star

WolfDiagram
type: Concept
definition: Wolf diagram
pref label: Wolf diagram
related: darkNebula
related: interstellarAbsorption

WolfRayetStar
type: Concept
broader: earlyTypeEmissionStar
definition: Wolf-Rayet star
narrower: WcStar
narrower: WcnStar
narrower: WnStar
narrower: WrStar
pref label: Wolf-Rayet star
related: OStar
related: carbonStar
related: circumstellarEnvelope
related: ejecta
related: massLoss

WrStar
type: Concept
broader: WolfRayetStar
change note: FVH: moved WOLF_RAYET_STARS to BT (2007-OCT-1)
definition: WR star
pref label: WR star

WUrsaeMajorisStar
type: Concept
broader: detachedBinaryStar
broader: eclipsingBinaryStar
definition: W Ursae Majoris star
pref label: W Ursae Majoris star
related: AlgolVariableStar

WVirginisStar
type: Concept
broader: populationIiCepheid
broader: pulsatingVariableStar
definition: W Virginis star
narrower: BlHerculisStar
pref label: W Virginis star
related: Cepheid
related: RrLyraeStar

WzSagittaeStar
type: Concept
broader: dwarfNova
broader: longPeriodVariableStar
definition: WZ Sagittae star
pref label: WZ Sagittae star
related: SuUrsaeMajorisStar

xenon
type: Concept
alt label: Xe
broader: fundamentalChemicalElement
definition: xenon (atomic number 54)
history note: FVH: new (2007-OCT-25)
pref label: xenon

XRayAbsorption
type: Concept
broader: XRaySpectrum
definition: X-ray absorption
pref label: X-ray absorption
related: XRayEmission

XRayAstronomy
type: Concept
broader: spaceAstronomy
definition: X-ray astronomy
pref label: X-ray astronomy
related: XRaySpectrograph
related: XRayTelescope
related: balloonBorneInstrument
related: rocketBorneInstrument
related: satelliteBorneInstrument
related: spaceObservatory

XRayBackground
type: Concept
broader: backgroundRadiation
definition: X-ray background
pref label: X-ray background
related: XRayRadiation
related: gammaRayBackground
related: microwaveBackground
related: radioBackground
related: ultravioletBackground

XRayBinaryStar
type: Concept
broader: XRaySource
broader: eruptiveBinaryStar
broader: interactingBinaryStar
definition: X-ray binary star
narrower: cataclysmicVariableStar
narrower: highMassXRayBinaryStar
narrower: lowMassXRayBinaryStar
pref label: X-ray binary star
related: HzHerculisStar
related: XRayBurst
related: XRayNova
related: XRayPulsar
related: XRayStar
related: blackHole
related: dwarfNova
related: neutronStar
related: symbioticStar

XRayBrightPoint
type: Concept
definition: X-ray bright point
pref label: X-ray bright point
related: closeBinaryStar
related: interactingBinaryStar

XRayBurst
type: Concept
broader: burst
definition: X-ray burst
pref label: X-ray burst
related: HzHerculisStar
related: XRayBinaryStar
related: XRayTransient
related: burster
related: gammaRayBurst
related: neutronStar
related: opticalBurst
related: radioBurst
related: rapidBurst

XRayContinuum
type: Concept
broader: XRaySpectrum
broader: continuumRadiation
definition: X-ray continuum
pref label: X-ray continuum

XRayDetector
type: Concept
broader: detector
definition: X-ray detector
pref label: X-ray detector
related: proportionalCounter

XRayDiffraction
type: Concept
broader: diffraction
definition: X-ray diffraction
pref label: X-ray diffraction
related: XRayScattering
related: XRaySpectroscopy

XRayEmission
type: Concept
broader: XRaySpectrum
broader: emissionSpectrum
definition: X-ray emission
pref label: X-ray emission
related: SunyaevZeldovichEffect
related: XRayAbsorption

XRayFlare
type: Concept
broader: flare
definition: X-ray flare
pref label: X-ray flare
related: activeGalaxy
related: activeStar

XRayFluorescence
type: Concept
broader: fluorescence
broader: photoluminescence
definition: X-ray fluorescence
pref label: X-ray fluorescence

XRayIdentification
type: Concept
definition: X-ray identification
pref label: X-ray identification
related: XRaySource
related: opticalIdentification

XRayLine
type: Concept
broader: emissionLine
definition: X-ray line
pref label: X-ray line
related: XRaySpectrum

XRayLuminosity
type: Concept
broader: luminosity
definition: X-ray luminosity
pref label: X-ray luminosity
related: highEnergyRadiation

XRayMap
type: Concept
broader: map
definition: X-ray map
pref label: X-ray map
related: XRayStructure

XRayNova
type: Concept
broader: nova
definition: X-ray nova
pref label: X-ray nova
related: XRayBinaryStar

XRayObservatory
type: Concept
broader: observatory
broader: spaceObservatory
definition: X-ray observatory
pref label: X-ray observatory

XRayPolarization
type: Concept
broader: lightPolarization
definition: X-ray polarization
pref label: X-ray polarization
related: polarizedRadiation

XRayPulsar
type: Concept
broader: pulsar
definition: X-ray pulsar
narrower: HzHerculisStar
pref label: X-ray pulsar
related: XRayBinaryStar
related: neutronStar
related: whiteDwarf

XRayQuasar
type: Concept
broader: quasar
definition: X-ray quasar
pref label: X-ray quasar

XRayRadiation
type: Concept
alt label: X-ray
broader: electromagneticRadiation
broader: highEnergyRadiation
broader: radiation
change note: FVH: moved X-ray to here (2007-OCT-8)
definition: X-ray radiation
pref label: X-ray radiation
related: XRayBackground
related: XRayScattering
related: XRaySource
related: XRaySpectrum

XRayScattering
type: Concept
broader: radiationScattering
definition: X-ray scattering
pref label: X-ray scattering
related: ComptonEffect
related: XRayDiffraction
related: XRayRadiation

XRaySource
type: Concept
broader: source
definition: X-ray source
narrower: RsCanumVenaticorumStar
narrower: XRayBinaryStar
narrower: activeGalacticNucleus
narrower: activeGalaxy
pref label: X-ray source
related: SeyfertGalaxy
related: XRayIdentification
related: XRayRadiation
related: XRayStar
related: eruptiveBinaryStar
related: opticalIdentification
related: quasar
related: radioGalaxy
related: relativisticStar
related: supernovaRemnant

XRaySpectrograph
type: Concept
alt label: X-ray spectrometer
broader: grazingIncidenceSpectrograph
broader: spectrograph
definition: X-ray spectrograph
pref label: X-ray spectrograph
related: XRayAstronomy

XRaySpectroscopy
type: Concept
broader: spectroscopy
definition: X-ray spectroscopy
pref label: X-ray spectroscopy
related: XRayDiffraction

XRaySpectrum
type: Concept
definition: X-ray spectrum
narrower: XRayAbsorption
narrower: XRayContinuum
narrower: XRayEmission
pref label: X-ray spectrum
related: XRayLine
related: XRayRadiation

XRayStar
type: Concept
broader: activeStar
broader: emissionLineStar
definition: X-ray star
pref label: X-ray star
related: XRayBinaryStar
related: XRaySource
related: radioStar

XRayStructure
type: Concept
definition: X-ray structure
pref label: X-ray structure
related: XRayMap

XRaySurvey
type: Concept
broader: survey
definition: X-ray survey
pref label: X-ray survey

XRayTelescope
type: Concept
broader: grazingIncidenceTelescope
broader: spaceTelescope
definition: X-ray telescope
pref label: X-ray telescope
related: XRayAstronomy

XRayTransient
type: Concept
definition: X-ray transient
pref label: X-ray transient
related: XRayBurst

YagiAntenna
type: Concept
broader: antenna
broader: directionalAntenna
broader: radioTelescope
definition: Yagi antenna
pref label: Yagi antenna
related: halfWaveDipole

yArray
type: Concept
broader: array
broader: radioInterferometer
definition: y-array
pref label: y array
related: tArray

year
type: Concept
definition: year
narrower: anomalisticYear
narrower: cosmicYear
narrower: tropicalYear
pref label: year
related: UniversalTime
related: ephemerisTime
related: lightYear
related: siderealTime
related: time

YerkesClassification
type: Concept
change note: FVH: removed NTs (2007-NOV-15)
definition: Yerkes galaxy classification scheme
history note: FVH: new (2007-OCT-12)
pref label: Yerkes classification
related: BGalaxy
related: DGalaxy
related: EGalaxy
related: EpGalaxy
related: IGalaxy
related: LGalaxy
related: NGalaxy
related: SGalaxy
related: cDGalaxy
related: galaxy

yokeMounting
type: Concept
broader: equatorialMounting
definition: yoke mounting
pref label: yoke mounting

youngDiskCepheid
type: Concept
broader: Cepheid
definition: young disc Cepheid UK
definition: young disk Cepheid
pref label: young disk Cepheid

youngStarCluster
type: Concept
broader: openStarCluster
definition: young star cluster
pref label: young star cluster
related: ObStar
related: TAssociation
related: populationIStar
related: youngStar

youngStar
type: Concept
broader: populationIStar
broader: star
definition: young star
narrower: BStar
narrower: OStar
narrower: ObStar
narrower: blueStragglerStar
narrower: preMainSequenceStar
pref label: young star
related: HIiRegion
related: ObAssociation
related: RAssociation
related: TAssociation
related: youngStarCluster
scope note: only the broad classes are shown below; specific type will be found under these, or from the hierarchical list

ytterbium
type: Concept
alt label: Yb
broader: fundamentalChemicalElement
broader: rareEarth
definition: ytterbium (atomic number 70)
history note: FVH: new (2007-OCT-25)
pref label: ytterbium

yttrium
type: Concept
alt label: Y
broader: fundamentalChemicalElement
broader: rareEarth
definition: yttrium (atomic number 39)
history note: FVH: new (2007-OCT-25)
pref label: yttrium

ZAndromedaeStar
type: Concept
broader: closeBinaryStar
broader: emissionLineStar
broader: shellStar
broader: symbioticStar
definition: Z Andromedae star
pref label: Z Andromedae star

ZCamelopardalisStar
type: Concept
broader: dwarfNova
definition: Z Camelopardalis star
pref label: Z Camelopardalis star
related: UxUrsaeMajorisStar
related: VySculpturisStar

ZeemanSplitting
type: Concept
alt label: line splitting
alt label: spectral line splitting
broader: magnetoOpticalEffect
definition: Zeeman splitting
pref label: Zeeman splitting
related: DopplerBroadening
related: PaschenBackEffect
related: StarkBroadening
related: lineBroadening
related: lineShift
related: naturalLineWidth
related: pressureBroadening

zenithDistance
type: Concept
definition: zenith distance
pref label: zenith distance
related: altitudeAngle
related: diurnalParallax
related: refractionAngle

zenithHourlyRate
type: Concept
definition: zenith hourly rate
pref label: zenith hourly rate
related: meteorShower

zenithTelescope
type: Concept
broader: refractingTelescope
broader: transitTelescope
change note: FVH: removed photographic_zenith_tube, moved zenith_tube to NT (2007-OCT-1)
definition: zenith telescope
narrower: zenithTube
pref label: zenith telescope
related: meridianObservation

zenithTube
type: Concept
alt label: photographic zenith tube
broader: zenithTelescope
definition: zenith tube
pref label: zenith tube

zenith
type: Concept
broader: pole
definition: zenith
pref label: zenith
related: celestialSphere
related: horizonCoordinateSystem
related: nadir

zeroAgeHorizontalBranch
type: Concept
definition: zero-age horizontal branch
pref label: zero-age horizontal branch
related: HertzsprungRussellDiagram
related: giantBranch
related: zeroAgeMainSequence

zeroAgeMainSequence
type: Concept
alt label: ZAMS
definition: zero-age main sequence
pref label: zero-age main sequence
related: HertzsprungRussellDiagram
related: mainSequence
related: zeroAgeHorizontalBranch

zeroPoint
type: Concept
definition: zero point
pref label: zero point
scope note: combine with other terms

zinc
type: Concept
alt label: Zn
broader: fundamentalChemicalElement
definition: zinc (atomic number 30)
history note: FVH: new (2007-OCT-25)
pref label: zinc

zirconiumStar
type: Concept
definition: zirconium star
pref label: zirconium star
related: SStar
related: giant
related: heavyMetalStar
related: molecularBand
related: zirconium

zirconium
type: Concept
alt label: Zr
broader: fundamentalChemicalElement
definition: zirconium (atomic number 40)
history note: FVH: new (2007-OCT-25)
pref label: zirconium
related: zirconiumStar

zodiacalDustCloud
type: Concept
definition: zodiacal dust cloud
pref label: zodiacal dust cloud
scope note: see zodiacal dust

zodiacalDust
type: Concept
broader: dust
definition: zodiacal dust
pref label: zodiacal dust
related: gegenschein
related: interplanetaryMatter
related: meteoroid
related: meteoroidDustCloud
related: zodiacalLight

zodiacalLight
type: Concept
definition: zodiacal light
pref label: zodiacal light
related: FCorona
related: gegenschein
related: interplanetaryMatter
related: lightScattering
related: nightSkyBrightness
related: radiationScattering
related: skyBrightness
related: zodiacalDust

zodiac
type: Concept
definition: zodiac
pref label: zodiac
related: EarthOrbit
related: astrology
related: constellation
related: ecliptic

zoneOfTotality
type: Concept
definition: zone of totality
pref label: zone of totality
related: solarEclipse
related: umbra

ZzCetiStar
type: Concept
broader: multiPeriodicVariableStar
broader: pulsatingVariableStar
broader: whiteDwarf
definition: ZZ Ceti star
pref label: ZZ Ceti star
related: HeIiIonizationZone
related: kappaMechanism
related: nonRadialPulsation