The Effect of Stellar Features on Atmospheric Retrievals of WASP-52b’s Transmission Spectrum
Date:
Abstract: Stellar inhomogeneities (unocculted starspots or faculae) are believed to influence exoplanet transmission spectroscopy. Therefore, modeling and retrieving stellar features is crucial for understanding the exoplanet’s atmospheric properties. In this study, we apply atmospheric retrievals on the optical to infrared (0.6–2.7 μm) transmission spectrum of the hot Jupiter WASP-52b observed with JWST NIRISS/SOSS instruments. Our objective is to measure its atmospheric chemical composition and study the influence of unocculted stellar features on the transmission spectrum using POSEIDON (a Bayesian atmospheric retrieval algorithm). Since WASP-52b presents significant stellar features and starspot crossing events during the transit, we introduce unocculted starspot or facula (fraction, temperature, and surface gravity as free parameters) in the retrieval process. We will present our retrieval result on atmospheric composition and stellar feature estimates. This work allows us to establish constraints on WASP-52b’s planetary atmosphere and the stellar feature of its host star.