Localizing flares to understand stellar magnetic fields and space weather in exo-systems

Abstract

Stars are uniform spheres, but only to first order. The way in which stellar rotation and magnetism break this symmetry places important observational constraints on stellar magnetic fields, and factors in the assessment of the impact of stellar activity on exoplanet atmospheres. The spatial distribution of flares on the solar surface is well known to be non-uniform, but elusive on other stars. We briefly review the techniques available to recover the loci of stellar flares, and highlight a new method that enables systematic flare localization directly from optical light curves. We provide an estimate of the number of flares we may be able to localize with the Transiting Exoplanet Survey Satellite (TESS), and show that it is consistent with the results obtained from the first full sky scan of the mission. We suggest that non-uniform flare latitude distributions need to be taken into account in accurate assessments of exoplanet habitability.

6 pages, 2 figures. Proceedings of the 2021 XMM-Newton workshop "A high-energy view of exoplanets and their environments" accepted to Astronomische Nachrichten

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