Search Publications
Overexpansion-dominated coronal mass ejection formation and induced radio bursts
Song, H. Q.; Cheng, X.; Ding, M. D. +1 more
Aims: Coronal mass ejections (CMEs) are the most fascinating explosions in the Solar System. Their formation is still not fully understood, however.
Methods: We investigated a well-observed CME on 2021 May 7 that showed a typical three-component structure and was continuously observed from 0 to 3 R⊙ by a combination of SDO/AIA…
Radio evidence for a shock wave reflected by a coronal hole
Bemporad, A.; Frassati, F.; Giordano, S. +4 more
We report the first unambiguous observational evidence in the radio range of the reflection of a coronal shock wave at the boundary of a coronal hole. The event occurred above an active region located at the northwest limb of the Sun and was characterized by an eruptive prominence and an extreme-ultraviolet wave steepening into a shock. The EUV ob…
Polarisation and source structure of solar stationary type IV radio bursts
Klein, Karl-Ludwig; Salas-Matamoros, Carolina
The reconfiguration of the magnetic field during and after a coronal mass ejection (CME) may be accompanied by radio emission from non-thermal electrons. In particular, stationary type IV bursts (also called storm continua) are emitted by electrons in closed magnetic configurations usually located in the wake of the outward-travelling CME. Althoug…
Electron acceleration and radio emission following the early interaction of two coronal mass ejections
Palmerio, E.; Magdalenić, J.; Kilpua, E. K. J. +6 more
Context. Coronal mass ejections (CMEs) are large eruptions of magnetised plasma from the Sun that are often accompanied by solar radio bursts produced by accelerated electrons.
Aims: A powerful source for accelerating electron beams are CME-driven shocks, however, there are other mechanisms capable of accelerating electrons during a CME erupt…
Extended radio emission associated with a breakout eruption from the back side of the Sun
Palmerio, E.; Kilpua, E. K. J.; Lynch, B. J. +1 more
Context. Coronal mass ejections (CMEs) on the Sun are the largest explosions in the Solar System that can drive powerful plasma shocks. The eruptions, shocks, and other processes associated to CMEs are efficient particle accelerators and the accelerated electrons in particular can produce radio bursts through the plasma emission mechanism.
Ai…
Analyzing the propagation of EUV waves and their connection with type II radio bursts by combining numerical simulations and multi-instrument observations
Dolla, L.; Downs, C.; Marqué, C. +1 more
Context. EUV (EIT) waves are wavelike disturbances of enhanced extreme ultraviolet (EUV) emission that propagate away from an eruptive active region across the solar disk. Recent years have seen much debate over their nature, with three main interpretations: the fast-mode magneto-hydrodynamic (MHD) wave, the apparent wave (reconfiguration of the m…
Variable emission mechanism of a Type IV radio burst
Kilpua, E. K. J.; Monstein, C.; Morosan, D. E. +1 more
Context. The Sun is an active star and the source of the largest explosions in the solar system, such as flares and coronal mass ejections (CMEs). Flares and CMEs are powerful particle accelerators that can generate radio emission through various emission mechanisms.
Aims: CMEs are often accompanied by Type IV radio bursts that are observed a…
Tracking of an electron beam through the solar corona with LOFAR
Strassmeier, K. G.; McKean, J. P.; Eislöffel, J. +88 more
The Sun's activity leads to bursts of radio emission, among other phenomena. An example is type-III radio bursts. They occur frequently and appear as short-lived structures rapidly drifting from high to low frequencies in dynamic radio spectra. They are usually interpreted as signatures of beams of energetic electrons propagating along coronal mag…
Estimation of a coronal mass ejection magnetic field strength using radio observations of gyrosynchrotron radiation
Carley, Eoin P.; Vilmer, Nicole; Simões, Paulo J. A. +1 more
Coronal mass ejections (CMEs) are large eruptions of plasma and magnetic field from the low solar corona into interplanetary space. These eruptions are often associated with the acceleration of energetic electrons which produce various sources of high intensity plasma emission. In relatively rare cases, the energetic electrons may also produce gyr…
Segmentation of photospheric magnetic elements corresponding to coronal features to understand the EUV and UV irradiance variability
Giono, G.; Zender, J. J.; Kariyappa, R. +5 more
Context. The magnetic field plays a dominant role in the solar irradiance variability. Determining the contribution of various magnetic features to this variability is important in the context of heliospheric studies and Sun-Earth connection.
Aims: We studied the solar irradiance variability and its association with the underlying magnetic fi…