Stellar Elemental Abundances for Exoplanet Research: A Case Study Using Spectral Synthesis

With the advent of powerful instruments such as the JWST, we are gaining incredible insight into the composition and atmospheric conditions of a growing number of exoplanets. However, these details are heavily dependent on our knowledge of the planet’s host star, with one of the most important parameters being the star’s chemical composition. Crucially, the chemical abundances of elements in the host star are assumed to be well-reflected in, if not identical to, their planets. In this poster, we describe a method of LTE spectral synthesis analysis used to calculate the stellar parameters and chemical abundances of several elements important to planetary formation and composition studies. The analysis was carried out on high-resolution optical to near-infrared archival spectra for three targets: HD 209458, WASP-77 A, and HD 189733. The three stars presented here were a pilot study to test the method; a full analysis of 27 FGKM stars that are scheduled to be observed by JWST in Cycle 1 is forthcoming.