Infrared Observations of Exoplanet Atmospheres

The study of extrasolar planet atmospheres elucidates the formation and migration history of planets and places the origin and evolution of Earth and the Solar System in a broader context. The last several years have seen rapid strides in this direction via routine detections of planetary transits, thermal emission, atmospheric circulation, and transmisission spectroscopy using both broadband photometry and spectroscopy. My dissertation employs all these techniques in an effort to investigate the atmospheric composition, structure, and dynamics of a broad range of exoplanet atmospheres. These observations focus on the infrared wavelengths where planet emission is strongest and molecular features are most prominent. I present transit, eclipse, and phase curve photometry of several hot Jupiters (upsilon Andromedae b, HD 209458b, and WASP-12b), and present spectroscopy for both WASP-12b (emission, observed at low resolution) and the cool, low-mass planet GJ 1214b (transmission at high resolution). This work will guide future observations and inform the next generation of models in preparation for future spectroscopy of ever smaller, cooler, and more Earthlike planets