Mining the time axis with TRON. II. MeerKAT detects a stellar radio flare from a distant RS CVn candidate

TL;DR

This paper reports the detection of a stellar radio flare from a distant RS CVn candidate using MeerKAT data, demonstrating the effectiveness of the TRON pipeline in mining archival radio observations for transient sources.

Contribution

It introduces a new detection of a stellar radio flare from a distant star, showcasing the application of the TRON pipeline to identify transient radio phenomena in archival MeerKAT data.

Findings

Detected a radio flare from a G-type star at 1334 pc

The flare's properties suggest electron cyclotron maser instability

The star is consistent with an RS CVn variable

Abstract

Medium-timescale (minutes to hours) radio transients are a relatively unexplored population. The wide field-of-view and high instantaneous sensitivity of instruments such as MeerKAT provides an opportunity to probe this class of sources, using image-plane detection techniques. The previous letter in this series describes our project and associated TRON pipeline designed to mine archival MeerKAT data for transient and variable sources. In this letter, we report on a new transient, a radio flare, associated with Gaia DR3 6865945581361480448, a G type star, whose parallax places it at a distance of 1334 pc. Its duration and high degree of circular polarization suggests electron cyclotron maser instability as the mechanism, consistent with an RS CVn variable.