The Sun as a Rosetta Stone for Understanding Star–Planet Interactions

Abstract The Sun serves as a unique and invaluable reference point, or “Rosetta Stone”, for the study of other planetary systems. As the only star that can be observed with high spatial and temporal resolution, the Sun provides critical insight into stellar structure and activity, exoplanet formation, and star–planet interactions. We demonstrate the efficiency of a multi-disciplinary approach to interpret phenomena observed in distant exoplanetary systems by analogy with the Sun-Earth system. By applying the Star-Planet Interaction (SPI) code to a highly accurate model of the host star constrained by asteroseismic observations and empirical stellar wind proxies, we show that it is possible to quantify the impact of the star’s rotation and gravitational-tidal interaction on the long-term evolution of exoplanets including the resulting atmospheric loss and its implications for habitability. Here we show results obtained for the case of the Sun and provide a powerful framework for interpreting the habitability potential of exoplanetary systems across the Galaxy.