Do we expect to find the Super-Earths close to the gas giants?

TL;DR

This study explores the dynamical interactions between Super-Earths and gas giants in protoplanetary discs, revealing conditions for resonant capture or trapping at the gap edge, with implications for exoplanet observations.

Contribution

It provides new insights into the orbital evolution and resonance capture mechanisms of Super-Earths and gas giants in gaseous discs, highlighting the effects of initial positions and eccentricities.

Findings

Super-Earths can be captured into interior mean-motion resonances with gas giants.

Super-Earths on external orbits are often trapped at the gap edge, avoiding resonance.

System stability depends on initial orbital parameters and eccentricity evolution.

Abstract

We have investigated the evolution of a pair of interacting planets embedded in a gaseous disc, considering the possibility of the resonant capture of a Super-Earth by a Jupiter mass gas giant. First, we have examined the situation where the Super-Earth is on the internal orbit and the gas giant on the external one. It has been found that the terrestrial planet is scattered from the disc or the gas giant captures the Super-Earth into an interior 3:2 or 4:3 mean-motion resonance. The stability of the latter configurations depends on the initial planet positions and on eccentricity evolution. The behaviour of the system is different if the Super-Earth is the external planet. We have found that instead of being captured in the mean-motion resonance, the terrestrial planet is trapped at the outer edge of the gap opened by the gas giant. This effect prevents the occurrence of the first order mean-motion commensurability. These results are particularly interesting in light of recent exoplanet discoveries and provide predictions of what will become observationally testable in the near future.