A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Descriptionaltbroadernarrowerrelated
O ASSOCIATIONS      (OAssociations)
STAR ASSOCIATIONS O CLUSTERS ,
OB ASSOCIATIONS
 
OB ASSOCIATIONS      (ObAssociations)
STAR ASSOCIATIONS O ASSOCIATIONS ,
YOUNG STARS
 
OBJECTIVE GRATINGS      (ObjectiveGratings)
DIFFRACTION GRATINGS ,
TRANSMISSION GRATINGS 		ECHELLE GRATINGS ,
REFLECTION GRATINGS
 
OBJECTIVE PRISMS      (ObjectivePrisms)
PRISMS SCHMIDT TELESCOPES
 
OBJECTIVES      (Objectives)
PRIMARY LENSES ,
PRIMARY MIRRORS 		OPTICAL TELESCOPES
Primary optics of telescopes.
 
OBLATENESS      (Oblateness)
ELLIPTICAL GALAXIES ,
EQUATORIAL BULGE ,
PLANETS ,
ROTATION
 
OBLIQUE ROTATORS      (ObliqueRotators)
Ap STARS ,
MAGNETIC STARS ,
SPECTRUM VARIABLE STARS
 
OBLIQUITY OF ECLIPTIC      (ObliquityOfEcliptic)
obliquity CELESTIAL EQUATOR ,
ECLIPTIC ,
ECLIPTIC PLANE ,
PHASE DEFECT ,
PRECESSION
 
  A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Descriptionaltbroadernarrowerrelated
OBSERVATIONAL COSMOLOGY      (ObservationalCosmology)
COLOR REDSHIFT RELATION ,
COSMOLOGICAL DISTANCE SCALE ,
GALAXY COUNTS ,
GALAXY DISTRIBUTION ,
HUBBLE LAW ,
OBSERVATIONS ,
RADIO SOURCE COUNTS ,
REDSHIFT ,
REDSHIFT DISTANCE RELATION
 
OBSERVATIONS      (Observations)
OPTICAL OBSERVATIONS DATA ACQUISITION ,
OBSERVATIONAL COSMOLOGY ,
OBSERVING TECHNIQUES ,
RESEARCH
Combine with other terms
 
OBSERVATORIES      (Observatories)
ANTARCTIC OBSERVATORIES ,
GAMMA RAY OBSERVATORIES ,
GEOPHYSICAL OBSERVATORIES ,
INFRARED OBSERVATORIES ,
OPTICAL OBSERVATORIES ,
RADIO OBSERVATORIES ,
SPACE OBSERVATORIES 		DOMES ,
PLANETARIA ,
SITE PROTECTION ,
SITE TESTING ,
TELESCOPES ,
X RAY OBSERVATORIES
Only the broad classes are shown below. Specific types will be found under these, or from the Hierarchical List.
 
OBSERVING TECHNIQUES      (ObservingTechniques)
methods of observation ASTROMETRY ,
INTERFEROMETRY ,
PHOTOMETRY ,
POLARIMETRY ,
RADIO ASTROMETRY ,
RADIO INTERFEROMETRY ,
SPECTROMETRY ,
SPECTROPHOTOMETRY ,
SPECTROSCOPY 		ASTRONOMICAL TECHNIQUES ,
DATA ACQUISITION ,
DATA PROCESSING ,
OBSERVATIONS ,
OCCULTATIONS ,
PHOTOGRAPHY
Only the broad classes are shown below. Specific types will be found under these, or from the Hierarchical List.
 
OB STARS      (ObStars)
EARLY TYPE STARS ,
YOUNG STARS 		B STARS ,
O STARS ,
OB SUPERGIANT STARS 		RUNAWAY STARS ,
YOUNG STAR CLUSTERS
 
OB SUPERGIANT STARS      (ObSupergiantStars)
EARLY TYPE SUPERGIANT STARS ,
OB STARS 		B SUPERGIANT STARS ,
O SUPERGIANT STARS
 
OCCULTATIONS      (Occultations)
RADIO OCCULTATIONS ANGULAR DIAMETERS ,
BINARY STARS ,
DIAMETERS ,
ECLIPSES ,
MOON ,
OBSERVING TECHNIQUES ,
PLANETS ,
TRANSITS
 
OCCULTING DISK      (OccultingDisk)
SEPARATION ,
VISUAL BINARY STARS
 
OCEANOGRAPHY      (Oceanography)
OCEAN TIDES
 
OCEAN TIDES      (OceanTides)
TIDES OCEANOGRAPHY
 
  A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Descriptionaltbroadernarrowerrelated
O CLUSTERS      (OClusters)
OPEN STAR CLUSTERS B STARS ,
O ASSOCIATIONS ,
O STARS
 
O DWARF STARS      (ODwarfStars)
DWARF STARS ,
O STARS
 
Oef STARS      (OefStars)
EARLY TYPE EMISSION STARS ,
O STARS 		EARLY TYPE STARS ,
Of STARS
 
Oe STARS      (OeStars)
EARLY TYPE EMISSION STARS ,
O STARS
 
Of STARS      (OfStars)
EARLY TYPE EMISSION STARS ,
O STARS 		Oef STARS
 
O GIANT STARS      (OGiantStars)
O STARS
 
OH ABSORPTION      (OhAbsorption)
INTERSTELLAR ABSORPTION HYDROXYL RADICAL
 
OH CLOUDS      (OhClouds)
INTERSTELLAR MATTER HYDROXYL RADICAL
 
OH EMISSION      (OhEmission)
HYDROXYL RADICAL
 
OH IR STARS      (OhIrStars)
GIANT STARS ,
INFRARED SOURCES ,
OH SOURCES 		HYDROXYL RADICAL ,
OH MASERS ,
VARIABLE STARS
 
  A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Descriptionaltbroadernarrowerrelated
OH LINES      (OhLines)
HYDROXYL RADICAL
 
OH MASERS      (OhMasers)
MASERS HYDROXYL RADICAL ,
OH IR STARS ,
SiO MASERS ,
WATER MASERS
Subtypes not included.
 
OH SOURCES      (OhSources)
RADIO SOURCES OH IR STARS HYDROXYL RADICAL
 
OLD STARS      (OldStars)
EVOLVED STARS POPULATION II STARS ,
PREGALACTIC STARS
 
O MAGNITUDE      (OMagnitude)
APPARENT MAGNITUDES FAR INFRARED RADIATION ,
INFRARED PHOTOMETRY
 
ON LINE SYSTEMS      (OnLineSystems)
DATA CENTERS ,
DATA PROCESSING
 
OORT CLOUD      (OortCloud)
oort comet cloud COMETS
 
OORT CONSTANTS      (OortConstants)
GALACTIC ROTATION ,
GALACTIC STRUCTURE
 
OORT FORMULAS      (OortFormulas)
GALACTIC ROTATION ,
GALACTIC STRUCTURE
 
OOSTERHOFF GROUPS      (OosterhoffGroups)
GLOBULAR STAR CLUSTERS ,
METAL ABUNDANCE ,
RR LYRAE STARS
 
  A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Descriptionaltbroadernarrowerrelated
OPACITY      (Opacity)
OPTICAL PROPERTIES KRAMERS OPACITY ,
ROSSELAND OPACITY 		ABSORPTION ,
ATMOSPHERES ,
NEGATIVE H ION ,
OPTICAL DEPTH ,
RADIATION ,
RADIATIVE TRANSFER ,
TRANSPARENCY
 
OPEN STAR CLUSTERS      (OpenStarClusters)
galactic clusters STAR CLUSTERS O CLUSTERS ,
YOUNG STAR CLUSTERS 		BLUE STRAGGLER STARS ,
MOVING CLUSTER PARALLAX ,
POPULATION I STARS ,
RADIANT [MOVING CLUSTER] ,
SPIRAL ARMS ,
STAR ASSOCIATIONS ,
TURNOFF POINT
 
OPEN UNIVERSE      (OpenUniverse)
COSMOLOGY BIG BANG THEORY ,
CLOSED UNIVERSE ,
STEADY STATE THEORY
 
OPIK THEORY      (OpikTheory)
NEBULAE ,
SUPERNOVAS
 
OPPOSITION      (Opposition)
CONJUNCTION ,
QUADRATURE ,
SYNODIC PERIOD ,
SYZYGY
Refers to planet positions.
 
OPTICAL BURSTS      (OpticalBursts)
BURSTS BURSTERS ,
GAMMA RAY BURSTS ,
RADIO BURSTS ,
X RAY BURSTS
Specifically from BURSTERS.
 
OPTICAL COMPONENTS      (OpticalComponents)
CORRECTOR PLATES ,
DIFFRACTION GRATINGS ,
FIELD CORRECTORS ,
GRISMS ,
INTERFERENCE FILTERS ,
LENSES ,
MIRRORS ,
OPTICAL FIBERS ,
OPTICAL FILTERS ,
OPTICAL WAVEGUIDES ,
OPTICAL WINDOWS [OPTICS]
Not a complete list of terms.
 
OPTICAL DEPTH      (OpticalDepth)
optical thickness ABSORPTION COEFFICIENT ,
GAS DENSITY ,
OPACITY
 
OPTICAL DESIGN      (OpticalDesign)
OPTICAL INSTRUMENTS
 
OPTICAL DOUBLE STARS      (OpticalDoubleStars)
visual double stars [1] ANGULAR SEPARATION
Use only for pair in chance alignment. Refer also to VISUAL BINARY STARS.
 
  A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Descriptionaltbroadernarrowerrelated
OPTICAL FIBERS      (OpticalFibers)
glass fibers OPTICAL COMPONENTS ,
OPTICAL WAVEGUIDES 		FIBER OPTICS ,
GLASS ,
OPTICAL INSTRUMENTS
 
OPTICAL FILMS      (OpticalFilms)
films [optical] ANTIREFLECTION COATINGS ,
THIN FILMS 		DICHROIC MIRRORS ,
INTERFERENCE FILTERS ,
LIGHT INTERFERENCE
 
OPTICAL FILTERS      (OpticalFilters)
color filters FILTERS ,
OPTICAL COMPONENTS 		INTERFERENCE FILTERS ,
PHOTOGRAPHIC FILTERS 		DICHROIC MIRRORS ,
LIGHT INTERFERENCE ,
OPTICAL WINDOWS [OPTICS] ,
PHOTOMETRY ,
ULTRAVIOLET FILTERS
 
OPTICAL FLARES      (OpticalFlares)
FLARES FLARE STARS ,
PROMINENCES
 
OPTICAL GLASS      (OpticalGlass)
GLASS ,
OPTICAL MATERIALS 		OPTICAL WINDOWS [OPTICS]
 
OPTICAL IDENTIFICATIONS      (OpticalIdentifications)
optical counterparts GAMMA RAY SOURCES ,
RADIO SOURCES ,
X RAY IDENTIFICATIONS ,
X RAY SOURCES
 
OPTICAL INSTRUMENTS      (OpticalInstruments)
optical equipment CAMERAS ,
CORONAGRAPHS ,
MONOCHROMATORS ,
OPTICAL SCANNERS ,
PHOTOMETERS ,
POLARIMETERS ,
SEEING MONITORS ,
SPECTROGRAPHS ,
TELESCOPES 		COLLIMATORS ,
FIELD CORRECTORS ,
HARTMANN TEST ,
LENSES ,
MIRRORS ,
MODULATION TRANSFER FUNCTION ,
OPTICAL DESIGN ,
OPTICAL FIBERS ,
OPTICAL MATERIALS ,
OPTICAL SYSTEMS ,
OPTICAL TESTING ,
OPTICAL TRANSFER FUNCTION ,
PRISMS
Only the broad classes are shown below. Specific types will be found under these, or from the Hierarchical List.
 
OPTICAL INTERFEROMETERS      (OpticalInterferometers)
stellar interferometers INTERFEROMETERS INTENSITY INTERFEROMETERS ,
MICHELSON INTERFEROMETERS 		LONG BASELINE INTERFEROMETERS
 
OPTICAL INTERFEROMETRY      (OpticalInterferometry)
light interferometry ,
stellar interferometry 		INTERFEROMETRY INTERFERENCE FRINGES ,
INTERFERENCE [WAVES] ,
LIGHT INTERFERENCE ,
LONG BASELINE INTERFEROMETRY ,
MICHELSON INTERFEROMETRY
 
OPTICAL MATERIALS      (OpticalMaterials)
GLASS ,
OPTICAL GLASS 		LENSES ,
MIRRORS ,
OPTICAL INSTRUMENTS
 
  A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Descriptionaltbroadernarrowerrelated
OPTICAL OBSERVATIONS      (OpticalObservations)
OBSERVATIONS OPTICAL OBSERVATORIES
 
OPTICAL OBSERVATORIES      (OpticalObservatories)
OBSERVATORIES OPTICAL OBSERVATIONS ,
OPTICAL TELESCOPES ,
SEEING MONITORS
 
OPTICAL OUTBURSTS      (OpticalOutbursts)
OUTBURSTS CATACLYSMIC VARIABLE STARS ,
FLARE STARS ,
NOVAS ,
SUPERNOVAS
NOT from BURSTERS.
 
OPTICAL PATHLENGTH      (OpticalPathlength)
REFRACTIVE INDEX
 
OPTICAL POSITIONS      (OpticalPositions)
ASTROMETRY
 
OPTICAL PROPERTIES      (OpticalProperties)
PROPERTIES ALBEDO ,
BRIGHTNESS ,
COLOR ,
OPACITY ,
REFRACTIVE INDEX 		BRIGHTNESS TEMPERATURE ,
DARKNESS ,
ISOTROPY ,
OPTICS ,
POLARIZATION [WAVES]
Not a complete list of terms.
 
OPTICAL PULSARS      (OpticalPulsars)
PULSARS RADIO PULSARS
 
OPTICAL RADAR      (OpticalRadar)
RADAR LASER RANGING ,
LASERS ,
LUNAR LASER RANGING ,
SATELLITE LASER RANGING
 
OPTICAL SCANNERS      (OpticalScanners)
OPTICAL INSTRUMENTS SPECTROPHOTOMETRY
 
OPTICAL SPECTROSCOPY      (OpticalSpectroscopy)
SPECTROSCOPY
 
  A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Descriptionaltbroadernarrowerrelated
OPTICAL SYSTEMS      (OpticalSystems)
ABERRATIONS ,
APERTURES ,
CHROMATIC ABERRATION ,
COMA ,
DISTORTION ,
FIELD CURVATURE ,
OPTICAL INSTRUMENTS
 
OPTICAL TELESCOPES      (OpticalTelescopes)
TELESCOPES AUTOMATIC PATROL TELESCOPES ,
MULTIPLE MIRROR TELESCOPES ,
NEW TECHNOLOGY TELESCOPES ,
REFLECTING TELESCOPES ,
REFRACTING TELESCOPES ,
VERY LARGE TELESCOPES 		CATADIOPTRIC SYSTEMS ,
CATOPTRIC SYSTEMS ,
DIOPTRIC SYSTEMS ,
EYEPIECES ,
OBJECTIVES ,
OPTICAL OBSERVATORIES ,
SECONDARY MIRRORS
 
OPTICAL TESTING      (OpticalTesting)
FIGURING ,
MODULATION TRANSFER FUNCTION ,
OPTICAL INSTRUMENTS ,
OPTICAL TRANSFER FUNCTION
 
OPTICAL TRANSFER FUNCTION      (OpticalTransferFunction)
otf TRANSFER FUNCTIONS MODULATION TRANSFER FUNCTION ,
OPTICAL INSTRUMENTS ,
OPTICAL TESTING
 
OPTICAL WAVEGUIDES      (OpticalWaveguides)
OPTICAL COMPONENTS ,
WAVEGUIDES 		OPTICAL FIBERS
 
OPTICAL WINDOWS      (OpticalWindows)
ATMOSPHERIC WINDOWS INFRARED WINDOWS ,
RADIO WINDOWS
Low absorption in atmosphere.
 
OPTICAL WINDOWS [OPTICS]      (OpticalWindowsOptics)
OPTICAL COMPONENTS OPTICAL FILTERS ,
OPTICAL GLASS
 
OPTICS      (Optics)
ACTIVE OPTICS ,
ADAPTIVE OPTICS ,
ASTRONOMICAL OPTICS ,
FIBER OPTICS 		ABERRATIONS ,
ADJUSTMENT ,
ANGULAR RESOLUTION ,
COLLIMATION ,
OPTICAL PROPERTIES ,
REFRACTIVE INDEX ,
RESOLUTION ,
TRANSMISSION
Combine with other terms
 
ORBITAL ELEMENTS      (OrbitalElements)
elements of orbits ANOMALY ,
APSIDES ,
CENTER OF MASS ,
ECCENTRICITY ,
INCLINATION ,
OSCULATORY ELEMENTS ,
PERIOD ,
POSITION ANGLE ,
SEMIMAJOR AXIS 		ACCELERATION ,
CELESTIAL MECHANICS ,
ORBITS ,
REGRESSION OF NODES
See also ORBITS
 
ORBITAL EVOLUTION      (OrbitalEvolution)
CELESTIAL MECHANICS
 
  A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Descriptionaltbroadernarrowerrelated
ORBITAL MOTIONS      (OrbitalMotions)
MOTION CELESTIAL MECHANICS ,
CIRCULAR ORBITS ,
ORBITAL VELOCITY ,
VISUAL BINARY STARS
 
ORBITAL THEORY      (OrbitalTheory)
CELESTIAL MECHANICS
 
ORBITAL VELOCITY      (OrbitalVelocity)
VELOCITY ANGULAR VELOCITY ,
ESCAPE VELOCITY ,
ORBITAL MOTIONS ,
ORBITS ,
TANGENTIAL VELOCITY
 
ORBIT DETERMINATION      (OrbitDetermination)
BINARY STARS ,
MULTIPLE STARS ,
PLANETS
 
ORBITING OBSERVATORIES      (OrbitingObservatories)
SPACE ASTRONOMY ,
SPACE GEODESY ,
SPACE OBSERVATORIES 		ARTIFICIAL SATELLITES ,
SPACE ASTROMETRY
 
ORBITS      (Orbits)
ELLIPTICAL ORBITS ,
GEOCENTRIC ORBITS ,
HELIOCENTRIC ORBITS ,
HYPERBOLIC ORBITS ,
KEPLERIAN ORBITS ,
OSCULATING ORBITS ,
PARABOLIC ORBITS ,
PERIODIC ORBITS ,
POLAR ORBITS 		ACCELERATION ,
APSIDAL MOTIONS ,
APSIDES ,
BINARY STARS ,
CELESTIAL MECHANICS ,
HIGH VELOCITY STARS ,
LOCAL STANDARD OF REST ,
MOTION ,
MULTIPLE STARS ,
N BODY PROBLEM ,
NODES ,
ORBITAL ELEMENTS ,
ORBITAL VELOCITY ,
PARABOLIC VELOCITY ,
PERIOD ,
PERTURBATION ,
PERTURBATION THEORY ,
PLANETS ,
POSITION ANGLE ,
ROCHE LIMIT ,
SCHWARZSCHILD METRIC ,
SYNCHRONOUS ROTATION ,
THREE BODY PROBLEM ,
TRAJECTORIES
See also ORBITAL ELEMENTS.
 
ORGANIC MATTER      (OrganicMatter)
ORGANIC MOLECULES
 
ORGANIC MOLECULES      (OrganicMolecules)
MOLECULES ,
ORGANIC MATTER 		INTERSTELLAR MOLECULES ,
MOLECULAR SPECTRA
 
ORIENTATION      (Orientation)
ADJUSTMENT ,
ALIGNMENT [OPTICS] ,
COLLIMATION ,
POSITION ANGLE
 
ORIGIN      (Origin)
CHEMICAL ELEMENTS ,
ELEMENT FORMATION ,
GALAXIES ,
LIFE ,
PLANETS ,
SOLAR SYSTEM
Combine with other terms
 
  A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Descriptionaltbroadernarrowerrelated
ORION POPULATION STARS      (OrionPopulationStars)
EARLY TYPE STARS ,
PREMAINSEQUENCE STARS
 
ORRERIES      (Orreries)
MODELS MOTION ,
PLANETARIA
 
ORTHOHYDROGEN      (Orthohydrogen)
MOLECULAR HYDROGEN PARAHYDROGEN
 
ORTHOSCOPIC EYEPIECE      (OrthoscopicEyepiece)
EYEPIECES
 
OSCILLATING UNIVERSE      (OscillatingUniverse)
COSMOLOGY FRIEDMANN UNIVERSE
 
OSCILLATIONS      (Oscillations)
AMPLITUDES ,
DECAY [OSCILLATIONS] ,
e FOLDING TIME ,
PENDULUMS ,
WAVES
Combine with other terms
 
OSCILLATOR STRENGTHS      (OscillatorStrengths)
f values LINE FORMATION ,
LINE WIDTHS ,
TRANSITION PROBABILITIES
 
OSCULATING ORBITS      (OsculatingOrbits)
ORBITS
 
OSCULATORY ELEMENTS      (OsculatoryElements)
ORBITAL ELEMENTS CELESTIAL MECHANICS ,
PERTURBATION
 
O STARS      (OStars)
EARLY TYPE STARS ,
OB STARS ,
YOUNG STARS 		O DWARF STARS ,
O GIANT STARS ,
O SUBDWARF STARS ,
O SUPERGIANT STARS ,
Oe STARS ,
Oef STARS ,
Of STARS 		EARLY TYPE VARIABLE STARS ,
O CLUSTERS ,
SPECTRAL TYPES ,
WOLF RAYET STARS
 
  A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Descriptionaltbroadernarrowerrelated
O SUBDWARF STARS      (OSubdwarfStars)
O STARS ,
SUBDWARF STARS
 
O SUPERGIANT STARS      (OSupergiantStars)
EARLY TYPE SUPERGIANT STARS ,
O STARS ,
OB SUPERGIANT STARS ,
SUPERGIANT STARS
 
OUTBURSTS      (Outbursts)
BURSTS ,
FLARES 		OPTICAL OUTBURSTS
 
OUTER PLANETS      (OuterPlanets)
jovian planets PLANETS INNER PLANETS
 
OUTGASSING      (Outgassing)
CRYOGENICS ,
VACUUM TECHNIQUES
 
OVERTONE FREQUENCIES      (OvertoneFrequencies)
harmonic overtones ,
overtones 		FOURIER ANALYSIS ,
FUNDAMENTAL FREQUENCY ,
HARMONIC FREQUENCIES ,
MULTIPERIODIC VARIABLE STARS ,
OVERTONE MODES
See SN for OVERTONE MODES. Also see HARMONIC FREQUENCIES.
 
OVERTONE MODES      (OvertoneModes)
overtones PULSATION MODES FUNDAMENTAL MODE ,
MULTIPERIODIC VARIABLE STARS ,
OVERTONE FREQUENCIES ,
PULSATING VARIABLE STARS
Of pulsation frequencies, not Fourier components of non- sinusoidal variations.
 
OXYGEN      (Oxygen)
Combine with other terms
 
OXYGEN BURNING      (OxygenBurning)
NUCLEAR FUSION ,
NUCLEOSYNTHESIS 		CARBON BURNING ,
HELIUM BURNING ,
HYDROGEN BURNING ,
STELLAR INTERIORS
 
OZONE LAYER      (OzoneLayer)
EARTH ATMOSPHERE
 
  A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Descriptionaltbroadernarrowerrelated
Thu Jul 3 15:11:37 2008