Tidal Decay and Disruption of Short-Period Gaseous Exoplanets

Many gaseous exoplanets in short-period orbits are on the verge or are actually in the process of tidal disruption. Analysis shows tides can drive most known hot Jupiters to spiral into their host stars. Thus, orbital decay and tidal disruption likely shape the observed distribution of close-in exoplanets and may even be responsible for producing the shortest-period rocky planets. However, the exact outcome for a disrupting planet depends on its internal response to mass loss and variable stellar insolation, and the accompanying orbital evolution can act to enhance or inhibit the disruption process. Understanding these coupled processes and making accurate predictions requires a model that includes both the internal and the orbital evolution of the planet. We use the robust Modules for Experimentation in Stellar Astrophysics code suite to model these processes. We show that the orbital evolution of a planet undergoing Roche Lobe Overflow (RLO) is largely determined by the core mass of the gas giant. Comparing our results to observed exoplanets indicates that gas giants undergoing RLO can leave behind remnants, allowing study of previously unknown properties of rocky cores