3:30–5:00 pm ERC 161
Title: Population-Level Planetary Physics
Abstract: As the exoplanet population grows we can begin to investigate the physics of planets as classes of astrophysical objects. For giant planets it has long been suggested from planet formation theory, and is seen in the solar system, that the planets should follow a mass-metallicity relation. Using thermal evolution models we determine the bulk metallicity of 150 transiting giant planets, showing new behavior, including that massive super-Jupiters are metal-enriched, and do not asymptote to stellar composition. This has major implications for atmospheric spectroscopy and planet formation. For the abundant sub-Neptunes, we have developed a new structure model that fully couples thermal evolution and many mass-loss mechanisms that potentially sculpt the "small planet" population. We generally find that mass-loss is slower than others have suggested. We find little role for "core-powered" escape for any of the sub-Neptunes, and that low-density super-puff planets are stable to XUV-driven escape, as they reside in a new XUV-driven mass-loss regime. We discuss our plans for population synthesis for sub-Neptunes and super-Earths in the coming year.
Zoom: https://uchicago.zoom.us/j/93608741174?pwd=W4lXrXadGKmxeISt9r0H1k5jLxhRNp.1
