Astrophysics Luncheon Seminar A Giant Planet around a White Dwarf: Adaptive Optics follow-up of Microlensing Events Presented by Joshua Blackman University of Tasmania Monday, September 23, 2019 12:00 noon in 169-336 and on Webex Abstract I will discuss the first detection of a giant planet orbiting a white dwarf primary. This object was detected using Keck/NIRC2 follow-up data of the microlensing event MOA 2010-BLG-477Lb. This Jupiter-mass exoplanet was detected in August 2010 and re-observed as part of NASA's Keck Key Strategic Mission Support (KSMS) program to characterize cold exoplanets discovered by microlensing. This program is the first large-scale trial of the exoplanet mass-measurement method to be used on the Wide Field Infrared Survey Telescope (WFIRST). High angular resolution Keck data obtained over three epochs (2015, 2016, and 2018) shows an unrelated sub-arcsecond blend star and no flux excess of the lens star, indicating the presence of the dense host. While there is some evidence for rocky planets, or planetesimals, orbiting white dwarf systems (eg. WD 1145+017 in 2015), this is the first instance of a gas giant orbiting a white dwarf primary. I will describe the methods through which this detection was made, together with other more recent results of the program. JPL Contact: Geoff Bryden (3-4692)   Site Manager: Webmaster: CL 08-3220