Transient Emissions from Radio-Active Stars: Implications for Wide-Field Radio Surveys

TL;DR

This paper reviews the variability of magnetically active stars, focusing on radio flares, their physical processes, and how upcoming wide-field radio telescopes can advance understanding of these transient emissions.

Contribution

It discusses recent findings on stellar radio flare emissions, emphasizing the potential of wide-field radio imaging telescopes to study transient stellar phenomena.

Findings

Radio stellar flares span 11 decades in wavelength and energy.

Recent results differentiate coherent and incoherent emission mechanisms.

Wide-field radio telescopes offer promising prospects for observing stellar transients.

Abstract

Variability is a common characteristic of magnetically active stars. Flaring variability is usually interpreted as the observable consequence of transient magnetic reconnection processes happening in the stellar outer atmosphere. Stellar flares have been observed now across 11 decades in wavelength/frequency/energy; such a large span implies that a range of physical processes takes place during such events. Despite the fact that stellar radio flares have long been recognized and studied, key unanswered questions remain. I will highlight what, in my opinion, are some of these questions. I will also describe recent results on stellar flare emissions at radio wavelengths, discussing the nature of coherent and incoherent emissions and the prospects of wide-field radio imaging telescopes for studying such events.