The Great Escape of A Giant Planet from Planetary Engulfment

When main-sequence stars expand into red giants, they are expected to engulf close-in planets. The absence of planets with short orbital periods around red clump stars has been interpreted as evidence that close planets around Sun-like stars do not survive the red giant branch phase of their host stars. Here, I present the discovery that a known close-in exoplanet actually orbits a red clump star and therefore has a ‘forbidden’ existence. As an unlikely survivor to its previously expanding host star, the planet may have avoided engulfment through a stellar merger of its host star that drastically altered the star’s evolution. This is the first confirmed close-in planet around a red clump star and it provides evidence for the role of non-canonical stellar evolution in the extended survival of late-stage exoplanetary systems.