Seminar Series

Friends of Hot Jupiters. How do stellar companions influence hot Jupiter formation and migration?

Henry Ngo, California Institute of Technology

25 Aug 2016 - 15:30

Hot Jupiters are gas giant planets orbiting around other stars at very small semi-major axes (~0.05 AU) and short orbital periods (a few days). Our “Friends of Hot Jupiters” imaging campaign uses the Keck telescope’s adaptive optics system to search for stellar companions around hot Jupiter host stars. We find that almost half of hot Jupiter host stars have stellar companions between 50-2000 AU, approximately three times as large as the field star multiplicity rate. The increased binary fraction for hot Jupiter host stars suggests that either multi-stellar systems are more favorable sites for gas giant planet formation at all separations, or that the presence of a stellar companion preferentially causes the inward migration of gas giant planets via dynamical processes such as Kozai-Lidov oscillations. Using our survey data and averaging over initial semi-major axes between 1-5 AU, we constrain the maximum fraction of hot Jupiters that could have migrated inward via Kozai-Lidov oscillations to be less than 20%. I will also discuss our new imaging survey to find giant planets around low mass stars.

LCO Seminar Series,
6740 Cortona Dr, Suite 102,
Goleta, CA 93117