Localizing Stellar Activity on Low-Mass Stars with the Transiting Exoplanet Survey Satellite

Magnetic reconnection is the underlying cause of stellar flares, which are more likely to occur in regions of high magnetic activity, such as star spots. The rapid rotation and deep convection of young low-mass stars leads to heightened magnetic activity and a substantial increase in the rate of flares. By further understanding stellar activity, we are able to constrain how they affect observations such as radial velocity measurements and transmission spectroscopy. We analyze 120-second cadence light curves of young low-mass stars observed by the Transiting Exoplanet Survey Satellite (TESS) to investigate trends in flare times and frequency in relation to star spot modulation signals. TESS constantly monitors nearby stars, enabling the study of this flare-spot connection for a variety of star parameters such as age, temperature, and rotation rate. Trends in flare properties and spot modulation can provide a means to "localize" on which face of a star flares occur more frequently and better understand their association with active regions. We present a preliminary analysis of light curves from M and K dwarfs with no companions from five nearby and young moving groups: \beta Pictoris, AB Doradus, Tucana-Horologium, Columba, and Carina, spanning ages \sim 20 to 150 Myr. We discuss our techniques to analyze the distribution of flares across the rotation phase for stars in this sample and describe future improvements. 

Theme(s): The Sun and Cool Stars in the Time Domain, Cool Stars as Stellar Systems