Long-period Giant Companions to Three Compact, Multiplanet Systems

April 2019 • 2019AJ....157..145M

Authors • Mills, Sean M. • Howard, Andrew W. • Weiss, Lauren M. • Steffen, Jason H. • Isaacson, Howard • Fulton, Benjamin J. • Petigura, Erik A. • Kosiarek, Molly R. • Hirsch, Lea A. • Boisvert, John H.

Abstract • Understanding the relationship between long-period giant planets and multiple smaller short-period planets is critical for formulating a complete picture of planet formation. This work characterizes three such systems. We present Kepler-65, a system with an eccentric (e = 0.28 ± 0.07) giant planet companion discovered via radial velocities (RVs) exterior to a compact, multiply transiting system of sub-Neptune planets. We also use precision RVs to improve mass and radius constraints on two other systems with similar architectures, Kepler-25 and Kepler-68. In Kepler-68 we propose a second exterior giant planet candidate. Finally, we consider the implications of these systems for planet formation models, particularly that the moderate eccentricity in Kepler-65's exterior giant planet did not disrupt its inner system.


IPAC Authors


Benjamin Fulton

Assistant Scientist