Making systems of Super Earths by inward migration of planetary embryos

Abstract

Using N-body simulations with planet-disk interactions, we present a mechanism capable of forming compact systems of hot super Earths such as Kepler 11. Recent studies show that outward migration is common in the inner parts of radiative disks. However we show that two processes naturally tip the balance in favor of inward migration. First the corotation torque is too weak to generate outward migration for planetary embryos less massive than $4\mearth$. Second, system of multiple embryos generate sustained non-zero eccentricities that damp the corotation torque and again favor inward migration. Migration and accretion of planetary embryos in realistic disks naturally produce super Earths in resonant chains near the disk inner edge. Their compact configuration is similar to the observed systems.

4 pages, 3 figures, to appear in the Proceedings of IAU Symp. 299: Exploring the Formation and Evolution of Planetary Systems (Victoria, Canada)

References in corpus (4)

• Planet Occurrence within 0.25 AU of Solar-type Stars from Kepler
• A Closely-Packed System of Low-Mass, Low-Density Planets Transiting Kepler-11
• Migration and the formation of systems of hot super-Earths and Neptunes
• Orbital migration of interacting low-mass planets in evolutionary radiative turbulent models

Cited by in corpus (6)

• An Earth-sized Planet in the Habitable Zone of a Cool Star
• Hot super-Earths and giant planet cores from different migration histories
• No universal minimum-mass extrasolar nebula: Evidence against in-situ accretion of systems of hot super-Earths
• Terrestrial Planet Formation at Home and Abroad
• Inside-Out Planet Formation. III. Planet-disk interaction at the dead zone inner boundary
• Inside-Out Planet Formation. V. Structure of the Inner Disk as Implied by the MRI