Ultraviolet (UV)/extreme ultraviolet (EUV) emissions

MeerKAT imaging spectroscopy reveals multiple electron acceleration sites in a solar flare by Luo et al.

June 9, 2026

Solar flares are the most explosive energy-release events in the solar corona, leading to intense particle acceleration, plasma heating, and bulk plasma motions on short timescales. Core questions during solar flares remain unresolved, including how and where particle acceleration occurs, and how energized electrons propagate through coronal magnetic structures. Radio observations, due to their unique sensitivity to nonthermal and thermal electrons, serve as powerful diagnostics of electron dynamics and high-temperature […]

Energetics of compressive waves in the solar corona by Francesco Azzollini et al

July 2, 2024

Inelastic scattering off moving or oscillating density fluctuations leads to broadening of radio signals propagating in the solar corona and solar wind. Using an anisotropic density fluctuation model from the kinetic scattering theory for solar radio bursts, we deduce the plasma velocities (perpendicular to the line of sight) required to explain observations of spacecraft signal frequency broadening. The kinetic energy associated with these inferred bulk velocities cascades to smaller and […]

Searching for optical/EUV counterparts of type IIs in a complex metric burst 
by Costas Alissandrakis et al.*

December 7, 2021

Solar type II bursts are sporadic emissions characterized by their narrow bandwidth and slow frequency drift in dynamic spectra (Nelson & Melrose, 1985; Vršnak & Cliver 2008; Nindos et al. 2008; Pick & Vilmer 2008). They are attributed to shock waves produced by flare/CME eruptions. However, the association of type IIs with optical or EUV features is not clear; the leading edge or flanks of CMEs, the front of an […]

Localized Microwave and EUV Bright Structures in an Eruptive Prominence by J. Huang et al.*

July 30, 2019

We study a solar eruptive prominence with flare/coronal mass ejection (CME) event by microwave and extreme ultraviolet (EUV) observations. Its evolution can be divided into three phases: slow rise, fast expansion, and ejection. In the slow-rise phase, the prominence continuously twists for more than one hour with a patch of bright emission appearing around the top. When the north leg interacts with the local small-size loops, the fast expansion is […]

Large area solar flare ribbons as the model to explain puzzling millimeter emission by G.G. Motorina et al.*

March 12, 2019

Solar flares are sudden explosive processes, that convert the energy of the magnetic field into the kinetic energy of electrons and ions. Since the beginning of the century, millimeter observations of solar flares became routinely possible at a few frequencies with limited spatial resolution (see Kaufmann 2012, as a review). One of the most puzzling aspects of the observations at millimeter wavelengths (200-400 GHz) is the presence, in some flares, […]