Case Study of a Super-eccentric Warm Jupiter Migrating via Equilibrium and Dynamical Tides

A leading theory for hot Jupiter formation is high-eccentricity migration, in which planets are born at large separations and excited to near-unity eccentricities, creating extreme tidal dissipation that shrinks and circularizes their orbits. The most direct evidence for this scenario is the detection of highly eccentric planets caught in the act of migrating. Although such planets are rare, the recent discovery of TIC 241249530 b - a super-eccentric (e = 0.94) and retrograde hot Jupiter progenitor - presents an ideal case study to explore high-eccentricity migration and the accompanying tidal physics. In this paper, we examine the migration history of TIC 241249530 b and test two different models of tidal dissipation: equilibrium tides and chaotic dynamical tides. We show that TIC 241249530 b's properties can be explained by high-eccentricity migration triggered by von Zeipel-Lidov-Kozai oscillations induced by the observed distant binary star in the system, but only if the dominant tidal dissipation takes the form of equilibrium tides. Chaotic dynamical tides fail to explain the system because they require the planet to have migrated substantially closer to its star.