On the Interaction between a Protoplanetary Disk and a Planet in an Eccentric Orbit: Application of Dynamical Friction

TL;DR

This paper introduces an analytic method using dynamical friction to study how planets with high eccentricity interact with protoplanetary disks, providing a new tool for understanding planet migration and eccentricity damping.

Contribution

The paper develops a novel analytic approach that applies dynamical friction to model disk-planet interactions for highly eccentric planets, extending previous methods.

Findings

The method agrees with previous results for moderate eccentricities.

Orbital evolution timescales vary significantly with disk models for high eccentricity planets.

The approach can be applied to arbitrary large eccentricities.

Abstract

We present a new analytic approach to the disk-planet interaction that is especially useful for planets with eccentricity larger than the disk aspect ratio. We make use of the dynamical friction formula to calculate the force exerted on the planet by the disk, and the force is averaged over the period of the planet. The resulting migration and eccentricity damping timescale agrees very well with the previous works in which the planet eccentricity is moderately larger than the disk aspect ratio. The advantage of this approach is that it is possible to apply this formulation to arbitrary large eccentricity. We have found that the timescale of the orbital evolution depends largely on the adopted disk model in the case of highly eccentric planets. We discuss the possible implication of our results to the theory of planet formation.