Exoplanets that transit their host stars as seen from earth present observational opportunities to probe the properties of the planet beyond just mass and/or radius. Since 2005, transit and eclipse observations with ground- and space-based (HST, Spitzer) facilities have provided important insights into exoplanet atmospheric composition and thermal structure. The majority of transiting planets amenable to atmospheric characterization observations orbit close to their host stars, well within the tidal locking radius. This orbital configuration naturally leads to large atmospheric thermal gradients that make it difficult to capture the true nature of a planet’s atmosphere with transit and eclipse observations alone. Phase-curve, eclipse-mapping, and transit-mapping observations require a greater level of precision, but provide a window into the fundamentally three-dimensional nature of exoplanet atmospheres. Such high-precision observations of highly eccentric systems have also allowed us to probe interactions between the planet and its host star (both radiative and gravitational). Here I will review recent result of phase-curve and eclipse-mapping observational campaigns with Spitzer and discuss prospects for probing planets using such techniques with JWST.
POC: Tom Greene / Tom.Greene@nasa.gov