Simulations reveal hydrodynamics of planetary engulfment by expanding star

A new study using hydrodynamical simulations reveals the forces acting on a planet when it is swallowed by an expanding star. The results show that the interactions of a substellar body (a planet or brown dwarf) with the hot gas in the outer envelope of a sun-like star can lead to a range of outcomes depending on the size of the engulfed object and the stage of the star’s evolution. The dynamics and possible outcomes of planetary engulfment are poorly understood, but it is thought to be a relatively common fate for planetary systems.