Terrestrial Planet Formation in the Presence of Migrating Super-earths

Abstract

Super-Earths with orbital periods less than 100 days are extremely abundant around Sun-like stars. It is unlikely that these planets formed at their current locations. Rather, they likely formed at large distances from the star and subsequently migrated inward. Here we use N-body simulations to study the effect of super-Earths on the accretion of rocky planets. In our simulations, one or more super-Earths migrates inward through a disk of planetary embryos and planetesimals embedded in a gaseous disk. We tested a wide range of migration speeds and configurations. Fast-migrating super-Earths (${\tau }_{mig}\sim$0.01-0.1 Myr) only have a modest effect on the protoplanetary embryos and planetesimals. Sufficient material survives to form rocky, Earth-like planets on orbits exterior to the super-Earths'. In contrast, slowly migrating super-Earths shepherd rocky material interior to their orbits and strongly deplete the terrestrial planet-forming zone. In this situation any Earth-sized planets in the habitable zone are extremely volatile-rich and are therefore probably not Earth-like.

Accepted for publication in The Astrophysical Journal; proof corrected version

References in corpus (28)

• Habitable Zones Around Main-Sequence Stars: Dependence on Planetary Mass
• The Occurrence and Mass Distribution of Close-in Super-Earths, Neptunes, and Jupiters
• Habitable planets around the star Gl 581?
• Solar System evolution from compositional mapping of the asteroid belt
• Building Terrestrial Planets
• Origins of Eccentric Extrasolar Planets: Testing the Planet-Planet Scattering Model
• Migration and the formation of systems of hot super-Earths and Neptunes
• An Earth-sized Planet in the Habitable Zone of a Cool Star
• Halting Type I planet migration in non-isothermal disks
• Kepler-62: A five-planet system with planets of 1.4 and 1.6 Earth radii in the Habitable Zone
• Three-dimensional simulations of multiple protoplanets embedded in a protostellar disc
• On the corotation torque in a radiatively inefficient disk
• Exotic Earths: Forming Habitable Worlds with Giant Planet Migration
• A decreased probability of habitable planet formation around low-mass stars
• Resonant Repulsion of Kepler Planet Pairs
• Cavity opening by a giant planet in a protoplanetary disc and effects on planetary migration
• Bayesian search for low-mass planets around nearby M dwarfs. Estimates for occurrence rate based on global detectability statistics
• Observable Consequences of Planet Formation Models in Systems with Close-in Terrestrial Planets
• On disc protoplanet interactions in a non-barotropic disc with thermal diffusion
• On the formation of terrestrial planets in hot-Jupiter systems
• Growing and moving low-mass planets in non-isothermal disks
• Building Giant-Planet Cores at a Planet Trap
• Formation, tidal evolution and habitability of the Kepler-186 system
• The effect of type I migration on the formation of terrestrial planets in hot-Jupiter systems
• Traditional formation scenarios fail to explain 4:3 mean motion resonances
• The Effect of Planets Beyond the Ice Line on the Accretion of Volatiles by Habitable-Zone Rocky Planets
• The circulation of dust in protoplanetary discs and the initial conditions of planet formation
• Resonances of Multiple Exoplanets and Implications for Their Formation

Cited by in corpus (18)

• Formation of planetary systems by pebble accretion and migration: How the radial pebble flux determines a terrestrial-planet or super-Earth growth mode
• Formation of planetary systems by pebble accretion and migration: Growth of gas giants
• The nature and origins of sub-Neptune size planets
• The period ratio distribution of Kepler's candidate multiplanet systems
• Gas giant planets as dynamical barriers to inward-migrating super-Earths
• The Exoplanet Radius Valley from Gas-driven Planet Migration and Breaking of Resonant Chains
• Solar System Physics for Exoplanet Research
• Kuiper belt structure around nearby super-Earth host stars
• A $75\%$ Occurrence Rate of Debris Discs around F stars in the $\beta$ Pic Moving Group
• Evolutionary outcomes for pairs of planets undergoing orbital migration and circularization: second order resonances and observed period ratios in Kepler's planetary systems
• A Volatile-Poor Formation of LHS 3844b based on its Lack of Significant Atmosphere
• Origin and dynamical evolution of the asteroid belt
• Water delivery to the TRAPPIST-1 planets
• Effects of Planetesimal Scattering: Explaining the Observed Offsets from Period Ratios 3:2 and 2:1
• Terrestrial Planets Formation under Migration: the Systems near 4:2:1 Mean Motion Resonance
• Formation of super-Earths and mini-Neptunes from rings of planetesimals
• Forming rocky exoplanets around K-dwarf stars
• Isolating the extreme debris disc signature -- explorations of eccentric extreme debris discs formed by giant impacts