A comprehensive survey of transiting exoplanet atmospheres with Spitzer/IRAC

Studying exoplanets affords us the opportunity to understand the sheer diversity of planets in different physical regimes; from close-in hot-jupiters to super-earths without solar system counterparts. We aim to use the statistical power of a large survey to test the theoretical predictions of exoplanet atmosphere properties. We classify the sample into groups and use the properties of individual planets within these groups to understand the collective diversity of our sample.

We use the Spitzer space telescope to observe the atmospheres of a diverse sample of two dozens of close-in gas giant exoplanets and we present our preliminary results. The sample spans ranges of mass and equilibrium temperature. The dominant absorbers at these observed wavelengths are water, methane and carbon monoxide, and we strive to test theoretical predictions of the abundances of these molecules using our survey. We conduct a uniform and detailed analyses of transiting exoplanet light curves using state-of-the art systematic corrections in the two warm Spitzer/IRAC bandpasses (at 3.6 and 4.5 microns). We compare our observations of the atmospheric signals to cloud-free atmospheric 1D models. Ultimately, our work places new constraints on diverse families of exoplanet atmospheres, as well as on possible formation and evolution scenarios.

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