William Welsh (SDSU) : The Kepler Search for Circumbinary Planets: Kepler-16 and Beyond

While engaged in its primary mission of exoplanet reconnaissance, Kepler has discovered over 2000 eclipsing binary stars. We are carefully measuring their eclipse times and have discovered that a sizable number of systems possess significant eclipse timing variations (ETVs), indicating the presence of (at least) a third body that is perturbing the binary orbit. The amplitude and period of the ETVs allow us to constrain the mass of the unseen third body: a small amplitude and a short period implies a nearby, low-mass object, perhaps substellar. The very recent discovery of the circumbinary planet Kepler-16b confirms that such planets do exist. While Kepler-16 was discovered via its transits over its eclipsing binary host stars, such transits require an extremely favorable orientation in the sky, and are thus expected to be rare. Fortunately, non-transiting circumbinary planets can be discovered through their ETV signal, and do not require a fortuitous configuration. In this talk I will highlight the discovery and characteristics of Kepler-16, and discuss our search for other circumbinary planets, both transiting and non-transiting, including some interesting candidate systems.