Gas giant planets as dynamical barriers to inward-migrating super-Earths

TL;DR

This study uses dynamical simulations to demonstrate that gas giant planets can prevent inward migration of super-Earths, explaining the rarity of hot super-Earths in systems with gas giants and providing testable predictions about planetary system compositions.

Contribution

The paper introduces a model showing gas giants as barriers to super-Earth migration, offering a new explanation for the distribution of close-in planets and the Solar System's unique architecture.

Findings

Gas giants block inward migration of super-Earths.

Systems with gas giants are less likely to have hot super-Earths.

Early formation of gas giants influences planetary system architecture.

Abstract

Planets of 1-4 times Earth's size on orbits shorter than 100 days exist around 30-50% of all Sun-like stars. In fact, the Solar System is particularly outstanding in its lack of "hot super-Earths" (or "mini-Neptunes"). These planets -- or their building blocks -- may have formed on wider orbits and migrated inward due to interactions with the gaseous protoplanetary disk. Here, we use a suite of dynamical simulations to show that gas giant planets act as barriers to the inward migration of super-Earths initially placed on more distant orbits. Jupiter's early formation may have prevented Uranus and Neptune (and perhaps Saturn's core) from becoming hot super-Earths. Our model predicts that the populations of hot super-Earth systems and Jupiter-like planets should be anti-correlated: gas giants (especially if they form early) should be rare in systems with many hot super-Earths. Testing this prediction will constitute a crucial assessment of the validity of the migration hypothesis for the origin of close-in super-Earths.