Simultaneous X-ray and optical flares of M dwarfs observed with eROSITA and TESS

We study the variability of M dwarfs using data collected simultaneously from the Transiting Exoplanet Survey Satellite (TESS) in the optical band and the extended ROentgen Survey with an Imaging Telescope Array (eROSITA) in X-rays. Both TESS and eROSITA perform an all-sky survey, with long exposure observations at the ecliptic poles. We selected M dwarfs from the two-minute target list in the TESS Southern Continuous Viewing Zone (SCVZ) for our sample. Here, we study a sub-sample with the brightest and most variable M dwarfs that have simultaneous TESS and eROSITA light curves and we present our first results on flares seen in both wavebands.