Coronal Mass Ejection (CME) – Page 3 – Community of European Solar Radio Astronomers

Variable Emission Mechanism of a Type IV Radio Burst
by D. Morosan et al.*

2019-04-23 390 views

Coronal mass ejections (CMEs) are sometimes accompanied by continuum emission at decimetric and metric wavelengths, called Type IV radio bursts. Of particular interest to determining CME properties are moving Type IV radio bursts, which are broadband radio sources moving outwards from the Sun. First studies suggested that moving Type IV bursts are emitted by synchrotron or gyro-synchrotron emitting electrons that are trapped inside CME loops (Dulk 1973). However, since their […]

Source Imaging of a Moving Type-IV Solar Radio Burst and its Role in Tracking Coronal Mass Ejection From the Inner to the Outer Corona
by Y. Chen et al.

2019-02-26 395 views

T-IV solar radio bursts are wideband continuum observed with dynamic spectrographs at metric to decametric wavelengths. They can be classified into static and moving ones, according to whether the sources remain basically static or move outward. The static ones are related to solar flares with frequencies extending up to GHz, while the moving ones (T-IVms) are related to coronal mass ejections (CMEs) with frequencies sometimes shifting to tens of MHz. […]

Coronal Mass Ejection-driven Type II solar radio burst structure with LOFAR and radio-wave scattering
by Nicolina Chrysaphi et al.*

2019-01-29 583 views

Coronal Mass Ejections (CMEs) are often viewed as the major drivers of space weather disturbances in the Sun-Earth system. Shocks driven by CMEs can excite radio emissions characterised by a slow frequency drift across dynamic spectra. These radio emissions are known as Type II solar radio bursts and can consist of two bands with a frequency ratio of 1:2. Each of these bands can split into two thinner sub-bands, a […]

Coronal mass ejections associated to a super-active region
by H. Cremades et al.*

2018-12-18 592 views

During its transit through central meridian, and along four consecutive days, from 13 to 16 February 2011, NOAA active region (AR) 11158 generated coronal mass ejections (CMEs) in association with waves observed in the extreme ultraviolet (EUV) low corona, and even with a Moreton wave. On those dates, the spacecraft of the STEREO mission were located in quadrature with SOHO and SDO, enabling the exceptional observation of this series of […]

Shock location and CME 3-D reconstruction of a solar type II radio burst with LOFAR
by P. Zucca et al.*

2018-10-30 361 views

Type II radio bursts are the result of shocks in the solar atmosphere and they can be observed ranging from sub-metric to kilometric wavelengths (~400 MHz to ~0.4 MHz). Coronal mass ejections initiate most of the metric type II (m-type II) bursts. The region of a CME responsible for driving the shock might be different for each event and has not yet been comprehensively identified. Multiple scenarios have been suggested, […]

Size distributions of solar proton events and their asso-ciated soft X-ray flares based on the maximum likelihood estimator
by E.W. Cliver and E. D’Huys

2018-09-18 357 views

It has been known for some time that the size distributions of solar radio bursts and soft X-ray (SXR) flares have steeper power-law slopes (~1.8) than those (~1.2) of solar energetic proton (SEP) events. Hudson (1978) suggested three possibilities for this difference: (1) proton flares are fundamentally different from ordinary flares; (2) proton flares represent the large end of the total energy distribution of ordinary flares; and (3) proton flare […]

An Extreme-ultraviolet Wave Generating Upward Secondary Waves in a Streamer-like Solar Structure
by Ruisheng Zheng et al.*

2018-08-07 329 views

Extreme-ultraviolet (EUV) waves are spectacular horizontally propagating disturbances in the low solar corona. If an EUV wave encounters an ambient coronal structure it may trigger another horizontal wave, which is always named a ‘secondary wave’ (SW). We present the first example of upward SWs in a streamer-like structure, a bright loop-like structure developing over an active region, after the passing of an EUV wave. The EUV wave was associated with […]

Long-lasting injection of solar energetic electrons into the heliosphere
by N. Dresing et al.

2018-07-24 297 views

The solar energetic particle (SEP) event from 26 Dec 2013 was a so-called widespread event observed by multiple spacecraft. The two STEREO and one close to Earth spacecraft spanned a total longitudinal angle of 210 degrees at that time. Together with the 25 Feb 2014 (Lario et al., 2016, Klassen et al., 2016) this is the widest event ever observed with the STEREO spacecraft. Unusually long-lasting SEP anisotropies together with […]

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