Analysis of M Dwarf Flaring with the Pictoris Moving Group

Current models of the habitable zone, while accounting for atmospheric contributions and the host star’s luminosity, rarely include effects due to flaring. Stellar flares occur stochastically as the magnetic field reorganizes and releases panchromatic radiation which often has a higher brightness temperature (~9-20 kK) than the star itself. The excess ultraviolet and X-ray emission has notable implications for observable exoplanetary phenomena including induced photochemistry and atmospheric loss. The exceptionally enhanced magnetic activity in young M dwarfs compared to earlier types and older stars leads to flaring events becoming a significant contributor to the radiation environment around the star. Accordingly, identifying the evolution of stellar flare characteristics is vital to fully understand the broader planetary context needed to interpret observations of exoplanet masses and radii and transmission spectra. As a well-populated and nearby stellar association, the beta Pictoris moving group (24 +/- 3 Myr) provides an ideal starting point for an investigation of M dwarf flares over time within the context of larger flare studies in which nuance due to metallicity and age effects become less distinct. We use TESS observations to characterize flare properties of 49 young K and M dwarfs, such as total energy and cumulative flare rate, and associate them with stellar properties. We successfully produce the ‘saturated’ upper limit with respect to rotation rate, similar flare-frequency power law relations, and inflated flare activity seen in large studies, confirming the calibration of our reduction pipeline for other moving groups and associations at different ages. The shallow power laws fitted (a = -1.58) are indicative of this population’s tendency to produce more large flares than older samples