The Space Physics of Star Planet Interactions

Exoplanet discoveries occur on an almost daily basis, with some 4000 planets already confirmed, a further 2000+ candidates in the wings and thousands more waiting to be discovered by the recently launched TESS mission. As we transition from a phase of discovery to one focused on detailed characterization and science, it is important to understand how stars and planets interact. Most of the Earth-size exoplanets detected to date are preferentially found in close-in orbits around small stars; Proxima Centauri b, Ross 128 b, and the TRAPPIST-1 planets are newly discovered exoplanets in this class. The effects of magnetic interactions between the host star and such close-in exoplanets are still not well-constrained. Yet the magnetic and energetic environment at an exoplanet and its impact on the magnetospheric-atmospheric coupling are important components of a planet’s habitability. In this talk, we discuss how our detailed knowledge of the Sun-Earth interaction is being used to explore the energetic impact of stellar activity on these new planet.