Speaker: Jonathan Fortney (UC Santa Cruz)

Host: Jake Simon

Title: Exoplanetary Atmospheres and the JWST Revolution

Abstract:  In this talk I will showcase new observations of close-in orbiting transiting planets, directly imagined planets, and isolated brown dwarfs from the James Webb Space Telescope (JWST), along with new modeling work to understand these observations.  For the first time, JWST has allowed high signal-to-noise spectra for these objects over a broad infrared wavelength range.  Giant planet atmospheres appear typically enriched in elements heavier than H and He, compared to their parent stars, which provides new insight on the planet formation process.  The roles of atmospheric mixing and photochemistry, which drive atmospheres away from chemical equilibrium molecular abundances, are ubiquitous in these atmospheres, as had been suggested from previous generations of atmosphere models. Lastly, I will discuss early observations of the hottest planet in the TRAPPIST-1 system of 7 Earth sized planets around a very low mass star, a system which is targeted by many early JWST programs.  All of these observations expand our phase phase of planetary atmospheric physics and chemistry, and help us place our solar system in context.