Presentation #102.107 in the session Poster Session.
High resolution cross-correlation spectroscopy (HRCCS) is an emerging method for characterizing exoplanets from the ground. It utilizes the planet signal’s time-resolved Doppler shift to disentangle it from the dominant telluric and stellar features. High spectral resolution combined with wide wavelength coverage allows for precise constraints on molecular abundances and thermal structure with novel atmospheric retrieval techniques. High resolution data can be combined with low resolution space-based data in retrieval, probing a wide range of altitudes and incorporating continuum information otherwise lost through detrending methods common in HRCCS. We present retrieval results of combined observations of a benchmark hot Jupiter WASP-77 Ab with both the IGRINS instrument on Gemini South (R ~ 45,000) and WFC3 on the Hubble Space Telescope (R ~ 100). We report a superstellar C/O ratio and a substellar metallicity, indicative of diverse formation pathways for hot Jupiters. We also report a bounded constraint on the carbon-12 to carbon-13 isotope ratio, the first such measurement for a transiting exoplanet.