Gas Giant Planets as Dynamical Barriers to Inward-Migrating Super-Earths
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.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 2015
- DOI:
- 10.1088/2041-8205/800/2/L22
- arXiv:
- arXiv:1501.06308
- Bibcode:
- 2015ApJ...800L..22I
- Keywords:
-
- planets and satellites: formation;
- planet–disk interactions;
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- Accepted for publication in ApJL