High-Resolution Spectroscopy of a Hot Jupiter

The composition of an exoplanet’s atmosphere provides a window into atmospheric structure and dynamics, as well as the formation history and evolution of the planet. Hot Jupiters, giant gaseous planets close to their host star, make an excellent laboratory for studying chemical compositions. High-resolution Infrared spectroscopy of hot Jupiters can resolve the Doppler shift of planetary absorption features relative to the stationary stellar and telluric ones. The presence of a molecule may be inferred by isolating the planetary signal and cross-correlating the spectrum with a model template containing the molecule. Over the past several years, this technique has led to the unambiguous detections of CO, H2O and TiO in hot Jupiter atmospheres. We present detections of molecular species in the atmosphere of HD189733 b. We use high-resolution (R ~ 100,000) dayside emission spectra acquired by the CRIRES spectrograph on board the VLT, and perform the cross-correlation with planetary atmospheric models to obtain high-significance detections of the molecular species.

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