Title: Exploring Planetary Formation and Stellar Activity via Gas Giants Observed with the James Webb Space Telescope
Speaker:
Jessica Libby-Roberts (Penn State)
Abstract:
Core accretion is a widely accepted theory for planetary formation as it is able to explain the variety of exoplanets discovered so far - albeit with several notable exceptions. One small population that stretches this theory are the low-mass and extremely low density super-puffs. These planets are roughly Jovian in size and yet possess only 1% the mass of Jupiter. How these planets managed to accrete and maintain an extended H/He atmosphere with a core of only several Earth masses remains an open question. On the other extreme end of planetary formation are the recently discovered and growing population of massive gas giants closely orbiting their low mass M-dwarf hosts. Current formational scenarios would require all dust present in protoplanetary disks to form these planets - a highly unlikely scenario. The planetary atmospheres of both populations may hold the necessary clues into the natal conditions of their formation. In this talk, I will present the James Webb Space Telescope (JWST) observed transmission spectra of the super-puff Kepler-51d and discuss the impact of this observation on our understanding of its formation and inflated radius. Second, I will showcase the JWST observed transmission spectra of several M-dwarf gas giants which are part of our large Cycle 2 program to characterize the atmospheres of seven of these planets. By leveraging the larger transit depths (>3%) and the NIRSpec/PRISM wide wavelength coverage, these JWST observations are also providing the first in-depth investigation into the impact of M-dwarf stellar contamination. Through our analyses of these spectra, we aim to not only better comprehend planetary formation of gas giants, but lay the groundwork for quantifying and minimizing stellar contamination in future JWST observed planetary transmission spectra.
