Community of European Solar Radio Astronomers

Connecting energetic electrons at the Sun and in the heliosphere through X-ray and radio diagnostics by D. Paipa-Leon et al.

2025-06-10

Solar flares accelerate energetic electrons. While some of them escape into interplanetary space and produce interplanetary Type III solar radio bursts, the electrons interacting with the solar atmosphere produce Hard X-ray emission (HXR). Many studies relating the observations of type III radio bursts and HXR emissions have been performed since the first observations of their temporal association (e.g., Kane 1972, 1981). More recently, statistical studies were done by https://www.aanda.org/articles/aa/full_html/2025/02/aa52278-24/aa52278-24.html and James & Vilmer (2023) […]

Synchrotron or not – analysis of two-part type II bursts by Silja Pohjolainen

2025-05-27

A distinct class of interplanetary (IP) type II bursts that show single-lane, wide-band diffuse emission has been identified, but how these bursts are formed is still unclear. The radio burst on June 17-18, 2003 was analysed by Bastian (2007) , who suggested that the wide-band and diffuse part of the burst (type II-S in Fig. 1) could be due to synchrotron emission. The later part of the burst (type II-P) […]

ALMA Observations of Solar Spicules in a Coronal Hole by T. S. Bastian et al.

2025-05-13

Solar spicules were discovered by the Jesuit priest Angelo Secchi in 1877. They are small plasma jets of a few hundred kilometers in diameter that are launched to heights >10 Mm with speeds ranging from a few 10s of km/s to >100 km/s. Individually they have lifetimes of a few minutes. They occur in the chromospheric network over the entirety of the Sun. Early estimates (Beckers 1972) suggested that spicules […]

Multi-spacecraft Radio Observations Trace the Heliospheric Magnetic Field by D. L. Clarkson et al.

2025-04-25

Solar flares accelerate energetic electrons that escape into interplanetary space, guided by the Parker spiral magnetic field, and are responsible for the generation of the interplanetary Type III solar radio bursts. With multiple spacecraft now in orbit around the Sun (see e.g. Musset et al 2021), we are in a unique position of observing the propagation of radio emission through the heliosphere from multiple vantage points. Recent study by Clarkson […]

X-ray/Radio Quasi-periodic Pulsations Associated with Plasmoids in Solar Flare Current Sheets by Kumar, Karpen, and Dahlin

2025-04-15

Plasmoids (or magnetic islands) are believed to play an important role in the onset of fast magnetic reconnection and particle acceleration during solar flares and eruptions. Direct imaging of flare current sheets and formation/ejection of multiple plasmoids in extreme ultraviolet (EUV) images, along with simultaneous X-ray and radio observations, provides significant insights into the mechanisms driving particle acceleration in solar flares. Previous studies have proposed that decimetric radio bursts and […]

Spectral Characteristics of Fundamental–Harmonic Pairs of Interplanetary Type III Radio Bursts Observed by PSP, by Ling Chen et al.

2025-04-01

Type III radio bursts are the most powerful and common type of solar radio bursts, shifting rapidly from high to low frequencies. In addition to the fast frequency drift from high to low frequencies, the fundamental–harmonic (F-H) frequency pairs’ structure in their dynamic spectra is the other most important observed feature of solar type III radio bursts. In this Letter, using the radio data observed by PSP during encounter phases […]

Magnetic Field Geometry and Anisotropic Scattering Effects to Explain Puzzling LOFAR Solar Radio Burst Observations by D. L. Clarkson et al.

2025-02-04

Solar radio bursts are an indirect signature of accelerated electron beams from the solar atmosphere. These fast electrons generate Langmuir waves as they propagate through a decreasing plasma density and ultimately lead to the bright broadband radio emissions with a characteristic fast frequency drift in dynamic spectra. Density turbulence in the plasma can modulate this process, producing fine structures such as sub-second, narrowband striae and spikes. These fine structures may […]

Flare Accelerated Electron Transport in Type III Solar Radio Bursts: large-scale transport and super-diffusive beam expansion by E. P. Kontar et al.

2025-01-21

Solar flares, the most powerful magnetic explosions in our solar system, are often accompanied by intense bursts of radio emission known as type III solar radio bursts. These bursts provide valuable clues about the acceleration and transport of energetic electrons in the Sun’s atmosphere and beyond. Understanding these bursts is not only crucial for solar physics but also for predicting space weather events that can disrupt our technological infrastructure. A […]