A Catalog of M-dwarf Flares with ASAS-SN

TL;DR

This study analyzed 1376 nearby M dwarfs using ASAS-SN data, identifying 62 flares and revealing correlations between flaring activity, spectral type, rotation, and H-alpha emission.

Contribution

It provides a comprehensive catalog of M-dwarf flares from ASAS-SN data and explores their relation to stellar properties, including rotation and emission features.

Findings

Flares observed on 62 stars with energies up to 6.9×10^{35} erg.

Flaring fraction increases with spectral type.

Flaring stars tend to have shorter rotation periods and stronger H-alpha emission.

Abstract

We analyzed the light curves of 1376 early-to-late, nearby M dwarfs to search for white-light flares using photometry from the All-Sky Automated Survey for Supernovae (ASAS-SN). We identified 480 M dwarfs with at least one potential flare employing a simple statistical algorithm that searches for sudden increases in $V$-band flux. After more detailed evaluation, we identified 62 individual flares on 62 stars. The event amplitudes range from $0.12 <\Delta V < 2.04$ mag. Using classical-flare models, we place lower limits on the flare energies and obtain $V$-band energies spanning $2.0\times10^{30} \lesssim E_{V} \lesssim 6.9\times10^{35}$ erg. The fraction of flaring stars increases with spectral type, and most flaring stars show moderate to strong H$\alpha$ emission. Additionally, we find that 14 of the 62 flaring stars are rotational variables, and they have shorter rotation periods and stronger H$\alpha$ emission than non-flaring rotational variable M dwarfs.