Do Sun-like stars swallow their own planets?
Lorenzo Spina (INAF-OAPD)
Tuesday 15/03/2022 @ 14:00, Remote talk
ow rare are planetary systems like our calm Solar System? Most exoplanetary systems did not form in their current configuration, but they have been heavily modified by non-trivial dynamical evolution. These processes have possibly destabilised planetary orbits in the most chaotic systems, forcing them to plunge into the host star. It has been proposed that these dramatic events, under some specific conditions, can modify the stellar chemical composition. In this talk, I will describe an experiment which has provided unambiguous evidence of planet engulfment events through the chemical analysis of Sun-like stars. Based on our analysis, we determine that planet engulfment events occur in a quarter of Sun-like stars. Indeed, a significant fraction of planetary systems undergo a very dynamical past, unlike our Solar System which has preserved its planets on nearly circular orbits. Our study also opens to the possibility of using the chemical analysis of stars to identify those that are more likely to host true analogues of our Solar System.