DIX Planetary Science Seminar

Flares and coronal mass ejections (CMEs) are more energetic than any other class of solar phenomena. They involve the rapid release of up to 10^33 erg of magnetic energy in the form of particle acceleration, heating, radiation, and bulk plasma motion. Displaying much larger energies, their stellar counterparts are expected to play a fundamental role in shaping the environmental conditions around low-mass stars, in some cases with catastrophic consequences for planetary systems due to processes such as of atmospheric evaporation and erosion. While flares are now routinely detected in multi-wavelength observations across all spectral types and ages, direct evidence for stellar CMEs is almost non-existent. In this context, numerical simulations provide a valuable pathway to shed some light on the eruptive behavior in the stellar regime. I will review recent results obtained from realistic modeling of CMEs in active stars, highlighting their key role in the interpretation of currently available observational constraints. Emphasis will be given to M dwarfs, focusing on how the emerging EUV/X-ray/Radio signatures from these events vary as a function of the magnetic properties of the star. I will also present our latest simulations of extreme CMEs from the flare star AU Mic, and how these energetic events are expected to affect the two recently discovered exoplanets of this system. Finally, I will discuss the implications and relevance of these numerical results in the context of future characterization of host star-exoplanet systems.