Institute of Astronomy

New Observations of Fomalhaut, Beta Pic and HR 4796A with HST and GPI

SpeakerTalk DateTalk Series
Paul Kalas30 July 2014Across HR 2014 Talks


High contrast imaging observations with HST show that the nearby star Fomalhaut is surrounded by a dusty debris belt and a candidate planet Fomalhaut b. Among the directly imaged exoplanets, Fomalhaut b has unexpected characteristics, such as a relatively blue spectrum and a highly eccentric orbit, leading to hypotheses that it is a gravitationally scattered, low-mass planet hosting a giant planetary dust ring or cloud seen in reflected light. Here we present new HST/STIS observations made in 2013 that authenticate the existence of Fomalhaut b at a fifth epoch. We discuss progress on several fronts, including the possible variability and spatial extent of Fomalhaut b, the existence of an azimuthal belt gap, and the probability that Fomalhaut b will physically intersect the belt over the next two decades. Also in 2013-2014, the Gemini Planet Imager (GPI) was successfully commissioned. I will review our new findings with GPI concerning the orbit of beta Pic b and its relationship to the warped debris disk, and present our analysis of belt structure and dust grain properties for HR 4796A.