Dynamics in Extreme Environments: From Lava to Tatooine Planets

par Mohammat Farhat (Berkeley)

jeudi 16 avr. 2026, 14:30 → 15:45 Europe/Paris

Salle Denisse (PARIS)

Planets in extreme astrophysical regimes are valuable laboratories for building a self-consistent picture of planet formation and evolution, because their orbital, geophysical, and thermodynamic conditions can reveal the governing physics most clearly. In this talk, I focus on two such regimes.

Orbiting at just a few stellar radii, ultra-short-period rocky planets experience intense irradiation and strong tidal interactions. Time-domain observations are beginning to resolve thermal emission patterns that encode coupled interior–surface–atmosphere processes. I will discuss how tidally driven lava waves can excite a sloshing magma ocean, depositing energy into the interior while reshaping surface temperature patterns and the planet’s thermal phase curve.

In the second regime, I address the apparent scarcity of circumbinary planets (CBPs). While early expectations suggested that CBPs should be as common as planets around single stars, only 14 transiting CBPs have been identified to date by Kepler and TESS. This dearth becomes a complete desert around the tightest binaries. I will propose a novel mechanism to explain these observed features, in which a non-linear secular resonance encountered over a system’s evolution drives the CBP toward dynamical instability, ejection, or engulfment by the binary.