Constraining Planetary Migration and Tidal Dissipation with Coeval Hot Jupiters

TL;DR

This paper uses the ages of hot Jupiter systems, especially young ones, to constrain models of planetary migration and tidal dissipation, revealing differences in dissipation rates across stellar populations.

Contribution

It provides a novel analysis of how system age influences hot Jupiter orbital properties, offering new constraints on tidal dissipation processes based on coeval systems.

Findings

Constraints on tidal dissipation consistent with field planets.

Higher early-time dissipation suggested for Hyades and Praesepe.

Age effects on orbital eccentricity and pile-up distribution analyzed.

Abstract

We investigate the constraints on the formation of, and tidal dissipation processes in, hot Jupiters (HJs) that can be inferred based on reliable knowledge of the age of a system or population. Particular attention is paid to the role of young systems (such as those in open clusters or star-forming regions) in such studies. For an ensemble of coeval HJ (or proto-HJ) systems, we quantify the effect of age on the distribution of orbital eccentricities with respect to orbital periods as well as the location of the observed "pile-up" feature. We expect the effects of pre-main-sequence stellar evolution to be important only if a substantial fraction of HJs approach their current orbits early in protostellar contraction (ages less than 10 Myr). Application to the HJs presently known in the cluster M67 yields constraints on the dissipation roughly consistent with those gleaned from planets in the field; for those in the Hyades and Praesepe, our results suggest a higher degree of dissipation at early times than that inferred from other populations.