Contributions > By speaker > Schmidt Stephen

It has been proposed that at least some hot Jupiters were once cool giant planets, though the difficulty of observing the time evolution of exoplanet systems has made this proposal impossible to directly evaluate. Using the Galactic velocity dispersion of their host stars, we quantify the typical ages of the hot Jupiter subpopulations inside, near, and outside the hot Jupiter period peak. We show that the subpopulations inside and near the peak are older than the outer subpopulation. We argue that most of the inside- and near-peak subpopulations were once cool giant planets that became hot Jupiters due to late-time dynamical instabilities no less than 1 Gyr after the dissipation of their parent protoplanetary disks. On the other hand, the subpopulation outside the period peak has both young and old hot Jupiters that arrived at their observed locations early in their systems' histories via disk migration.