Atmospheric Metallicity and C/O of HD 189733 b from High-resolution Spectroscopy

Abstract

We present high-resolution K -band emission spectra of the quintessential hot Jupiter HD 189733 b from the Keck Planet Imager and Characterizer. Using a Bayesian retrieval framework, we fit the dayside pressure–temperature profile, orbital kinematics, mass-mixing ratios of H 2 O, CO, CH 4 , NH 3 , HCN, and H 2 S, and the 13 CO/ 12 CO ratio. We measure mass fractions of logH 2 O = − 2.0 − 0.4 + 0.4 and logCO = − 2.2 − 0.5 + 0.5 , and place upper limits on the remaining species. Notably, we find logCH 4