Dr. James R. Graham
UC Berkeley
University of Florida Astronomy Colloquium - Jan. 14th, 2009
Direct Detection of Exoplanets
I will discuss current and future work related to the direction detection of extrasolar planets, including: 1) a program using the Advanced Camera for Surveys on the Hubble Telescope and; 2) the Gemini Planet Imager (GPI).
1) The 100 Myr-old A star Fomalhaut hosts a belt of dusty material with a morphology that implies the presence of a shepherding planet. The Hubble Space Telescope has detected a common proper motion companion, Fomalhaut b, with properties consistent with the predicted exoplanet. Two epochs of optical data that reveal Keplerian orbital motion. The mass of Fomalhaut b is less than three Jupiter masses: a more massive object would disrupt the dust belt and would have been detected in deep H and L' images obtained with the Keck and Gemini Observatories.
2) The Gemini Planet imager is an "extreme" adaptive optics system being designed and built for the Gemini Observatory. GPI combines precise and accurate wavefront control, diffraction suppression, and a speckle-suppressing science camera with integral field and polarimetry capabilities. GPI's primary science goal is the direct detection and characterization of young, Jovian-mass exoplanets. For systems younger than 2 Gyr exoplanets more massive than 6 Jupiter masses and semimajor axes beyond 10 AU are detected with completeness greater than 50%. GPI will also discover faint debris disks, explore icy moons and minor planets in the solar system, reveal high dynamic range main-sequence binaries, and study mass loss from evolved stars.