Investigating the possibility of reversing giant planet migration via gap edge illumination

TL;DR

This paper explores a novel method to slow down or reverse giant planet migration in protoplanetary discs by heating the gap edge with stellar radiation, potentially explaining the existence of gas giants at certain distances.

Contribution

It introduces the concept that stellar irradiation of the gap edge can significantly alter planetary migration, a novel approach not previously detailed.

Findings

Heating the gap edge can slow or reverse Type II migration.

Maximum stellar irradiation can induce migration reversal.

The method warrants further 3D hydrodynamic studies.

Abstract

A massive planet in a protoplanetary disc will open a gap in the disc material which acts as a transition between Type I and Type II planetary migration. Type II migration is slower than Type I migration, however it is still desirable to slow down Type II migration to allow gas giant planets with semi-major axis in the range 5 to 10AU to exist, similarly to our Solar system. We investigate a method of slowing down and reversing Type II migration by heating the outer gap edge due to incident radiation from the central star. Using an approximate vertically averaged heating method we find that Type II migration can be slowed or in extreme cases reversed if we assume near maximum allowed irradiation from the central star. Therefore, we believe this is a very interesting phenomenon that should be investigated in greater detail using three dimensional hydrodynamic and radiative transfer simulations.