Optical flares from the faint mid-dM star 2MASS J00453911+4140396

TL;DR

This paper reports on optical observations of a large stellar flare from a faint mid-dM star, revealing detailed light curves, energy estimates, and flare-like events that suggest solar-like triggering mechanisms.

Contribution

It provides the first detailed optical light curves and energy estimates of a large flare from a faint mid-dM star, highlighting possible solar-like triggering processes.

Findings

Total flare energy estimated at ~10^35 erg

Detection of three weak flare-like events during cooling phase

Evidence suggesting a solar-like triggering mechanism

Abstract

We present $B$ and $V$ light curves of a large stellar flare obtained with the Wide Field Camera at the Isaac Newton 2.5-m telescope (La Palma). The source object is a faint ($m_V=21.38$) foreground star in the field of the Andromeda galaxy, with its most probable spectral type being dM4. We provide an estimate of the total flare energy in the optical range and find it to be of the order of $10^{35}$ erg. The cooling phase of the large flare shows three additional weak flare-like events, which we interpret as results of a triggering mechanism also observed on the Sun during large coronal mass ejections.