The post-main sequence stellar evolution can have catastrophic consequences for orbiting planets. With the expansion of the star’s envelope during the red giant branch, some exoplanets are likely engulfed, producing changes in the surface chemical composition of the star. There are no clear chemical signatures that are unequivocally associated with this event, but the enhancement of light elements that should be depleted on the surface of red giants can be considered an indicator of engulfment (e.g., lithium or beryllium). Other observational signals that hint towards the accretion of substellar companions in red giant branch stars could be fast rotation rates, IR excess, photometric transients, and chromospheric activity. Associations and correlations between these different signatures could help us to identify engulfment events and better understand and characterize the interactions between planets and their host stars.
