Exploring Extreme Space Weather Factors of Exoplanetary Habitability

On the relative importance of AGN winds for the evolution of exoplanet atmospheres

“…Hu et al 2022), and Galactic cosmic rays might similarly affect habitability in the close vicinity of a strong cosmic ray sources (e.g. Airapetian et al 2018;Thomas & Ratterman 2020). A quantitative investigation of atmospheric chemistry and the effect of AGN-accelerated cosmic rays on the Galactic habitable zone is beyond the scope of this work, but we will briefly comment on the potential importance of AGN winds relative to other sources of energetic charged particles.…”

Radio Stars: From kHz to THz

“…As noted by Linsky, Osten, and other speakers, the question of exoplanet habitability goes far beyond the presence of liquid water, to matters such as the importance of CMEs (which may compress planetary magnetospheres, exposing their atmospheres to erosion) and whether various energetic processes (flares, ionized winds, pick-up processes, UV heating, and sputtering) might destroy ozone and otherwise impact the atmospheric chemistry of planets (e.g., Airapetian et al 2018). And importantly, not only do many late-type stars have significantly higher activity levels than the Sun (e.g., Shibayama et al 2013;Karmakar et al 2017), but as J. Villadsen reminded us, they may stay highly active for up to several Gyr, in contrast with the Sun, where activity levels fall steeply within a few hundred Myr past the zero age main sequence (see Guinan & Engle 2009).…”