IvS Seminar: Linus Heinke (12/12/2024)

Linus Heinke - "Atmospheric Characterization of Exoplanets: Transmission Spectroscopy of a warm sub-Saturn Across the Entire Accessible JWST Wavelength Range" (IvS seminar 12/12/2024)
Abstract: The launch of the James Webb Space Telescope (JWST) has started a new era in the study of exoplanetary atmospheres. Transmission spectroscopy is perhaps the most important of the indirect techniques used to characterize the atmosphere of planets, for which we cannot separate stellar and planetary emission. Transit spectra allow us to constrain the atmospheric structure at the terminator region, which includes molecular abundances and temperature. Getting to these constraints is non-trivial, however. First there is the challenge of data reduction, turning the timeseries of uncorrected JWST images into transit spectra, and then the challenge of fitting these spectra using atmospheric retrievals. In this seminar, I will first present an overview on this topic, highlighting some important science results obtained with JWST. Then I will shift to a case study of the warm sub-Saturn HAT-P-12b for which JWST transmission spectroscopy was obtained using JWST NIRISS SOSS, NIRSpec BOTS, and MIRI LRS, covering the entire accessible wavelength range.