8 March 2012
8 March 2012
Speaker: Josh Carter (CfA)
Title:Photodynamics with Kepler
Abstract:The study of extrasolar planets has entered its heyday with the deluge of data from NASA's Kepler mission. The exquisitely precise photometry and unchanging stare of the Kepler spacecraft has unveiled a diverse population of transiting exoplanetary and eclipsing stellar systems. Of these, those in dynamically-interacting few to many body systems (both stellar and planetary) have proven to be the most scientifically valuable. In particular, these systems can provide with photometry alone what is impractical, too costly, or too imprecise to be useful when acquired by other means (e.g., spectroscopy) -- mass information. The signature of mass (or mass ratio) is encoded in non-Keplerian eclipse morphologies. This morphology may be quite complex in hierarchical stellar systems (e.g., KOI-126), but, this added complexity can translate into accurate masses and radii for even very low-mass stars. With multi-planet systems - where the determination of planetary mass means confirmation - the variable eclipse profile is almost entirely observed with transit timing variations (e.g., Kepler-9, Kepler-11, Kepler-18) or a combination of stellar eclipse timing variations and transit timing variations in the case of transiting circumbinary planets (Kepler-16, Kepler-34, Kepler-35). I will review some of these information rich systems and describe the techniques (so called "photodynamics") that facilitated these discoveries. Finally, I will describe a new search, with a novel algorithm, for similar (or even more extreme) systems in the Kepler data and provide some preliminary results.