Accretion and Evolution of ~2.5 Earth-mass Planets with Voluminous H/He Envelopes

Abstract

Formation of planets in the Neptune size range with low-mass, but voluminous, H_2/He gaseous envelopes is modeled by detailed numerical simulations according to the core-nucleated accretion scenario. Formation locations ranging from 0.5 to 4 AU from a star of 1 solar mass are considered. The final planets have heavy-element cores of 2.2--2.5 Earth masses and envelopes in the range 0.037--0.16 Earth masses. After the formation process, which lasts 2 Myr or less, the planets evolve at constant mass up to an age of several Gyr. For assumed equilibrium temperatures of 250, 500, and 1000 K, their calculated final radii are compared with those observed by the Kepler spacecraft. For the particular case of Kepler-11 f, we address the question whether it could have formed in situ or whether migration from a formation location farther out in the disk is required.

arXiv comment32 pages, 6 figures, accepted for publication in The Astrophysical Journal

References in corpus (27)

• Planetary Candidates Observed by Kepler, III: Analysis of the First 16 Months of Data
• Evolution of the Solar Activity over Time and Effects on Planetary Atmospheres: I. High-energy Irradiances (1-1700 A)
• Mass-Radius Relationships for Solid Exoplanets
• Architecture and Dynamics of Kepler's Candidate Multiple Transiting Planet Systems
• Atmospheric Escape from Hot Jupiters
• A Closely-Packed System of Low-Mass, Low-Density Planets Transiting Kepler-11
• The Mass-Radius Relation for 65 Exoplanets Smaller than 4 Earth Radii
• Masses, Radii, and Orbits of Small Kepler Planets: The Transition from Gaseous to Rocky Planets
• Line and Mean Opacities for Ultracool Dwarfs and Extrasolar Planets
• The Minimum-Mass Extrasolar Nebula: In-Situ Formation of Close-In Super-Earths
• How Thermal Evolution and Mass Loss Sculpt Populations of Super-Earths and Sub-Neptunes: Application to the Kepler-11 System and Beyond
• Models of the in situ formation of detected extrasolar giant planets
• The Mass of KOI-94d and a Relation for Planet Radius, Mass, and Incident Flux
• Migration then assembly: Formation of Neptune mass planets inside 1 AU
• Models of Jupiter's Growth Incorporating Thermal and Hydrodynamic Constraints
• Formation and Structure of Low Density Exo-Neptunes
• Testing In Situ Assembly with the Kepler Planet Candidate Sample
• Planetary Candidates Observed by Kepler IV: Planet Sample From Q1-Q8 (22 Months)
• Density and Eccentricity of Kepler Planets
• In-situ Accretion of Hydrogen-Rich Atmospheres on Short-Period Super-Earths: Implications for the Kepler-11 Planets
• Formation of Jupiter using opacities based on detailed grain physics
• Overstable Librations can account for the Paucity of Mean Motion Resonances among Exoplanet Pairs
• Thermal evolution and structure models of the transiting super-Earth GJ 1214b
• All Six Planets Known to Orbit Kepler-11 Have Low Densities
• Gas Giant Formation with Small Cores Triggered by Envelope Pollution by Icy Planetesimals
• Period ratios in multi-planetary systems discovered by Kepler are consistent with planet migration
• The opacity of grains in protoplanetary atmospheres

Cited by in corpus (41)

• Most 1.6 Earth-Radius Planets are not Rocky
• Super-Earth Atmospheres: Self-Consistent Gas Accretion and Retention
• Make Super-Earths, Not Jupiters: Accreting Nebular Gas onto Solid Cores at 0.1 AU and Beyond
• To Cool is to Accrete: Analytic Scalings for Nebular Accretion of Planetary Atmospheres
• Atmospheres of low-mass planets: the "boil-off"
• Evolutionary Analysis of Gaseous Sub-Neptune-Mass Planets with MESA
• Kepler Planet Masses and Eccentricities from TTV Analysis
• Hydrodynamics of Embedded Planets' First Atmospheres. II. A Rapid Recycling of Atmospheric Gas
• The Formation of Super-Earths and Mini-Neptunes with Giant Impacts
• Habitable Evaporated Cores: Transforming Mini-Neptunes into Super-Earths in the Habitable Zones of M Dwarfs
• How formation time-scales affect the period dependence of the transition between rocky super-Earths and gaseous sub-Neptunes and implications for ${\eta }_{\oplus }$
• Atmosphere-interior exchange on hot rocky exoplanets
• Formation of close in Super-Earths \& Mini-Neptunes: Required Disk Masses \& Their Implications
• The mass of the Mars-sized exoplanet Kepler-138 b from transit timing
• Atmosphere Origins for Exoplanet Sub-Neptunes
• Habitability of Terrestrial-Mass Planets in the HZ of M Dwarfs. I. H/He-Dominated Atmospheres
• Gas giant planets as dynamical barriers to inward-migrating super-Earths
• The formation of mini-Neptunes
• The Compositional Diversity of Low-Mass Exoplanets
• Bright Opportunities for Atmospheric Characterization of Small Planets: Masses and Radii of K2-3 b, c, d and GJ3470 b from Radial Velocity Measurements and Spitzer Transits
• New Formation Models for the Kepler-36 System
• A Joint Mass-Radius-Period Distribution of Exoplanets
• Most super-Earths formed by dry pebble accretion are less massive than 5 Earth masses
• Doppler Monitoring of five K2 Transiting Planetary Systems
• Super-Earths and Earth-like Exoplanets
• Setting the Stage: Planet formation and Volatile Delivery
• Formation of compact systems of super-Earths via dynamical instabilities and giant impacts
• Habitable Evaporated Cores and the Occurrence of Panspermia near the Galactic Center
• Possibilities for an Aerial Biosphere in Temperate Sub Neptune-Sized Exoplanet Atmospheres
• Kepler-11 is a Solar Twin: Revising the Masses and Radii of Benchmark Planets Via Precise Stellar Characterization
• Where are the Water Worlds?: Self-Consistent Models of Water-Rich Exoplanet Atmospheres
• Trapping (sub-)Neptunes similar to TOI-216b at the inner disk rim: Implications for the disk viscosity and the Neptunian desert
• In Situ and Ex Situ Formation Models of Kepler 11 Planets
• Wolf 503 b: Characterization of a Sub-Neptune Orbiting a Metal-Poor K Dwarf
• Size evolution of close-in super-Earths through giant impacts and photoevaporation
• Exoplanet atmosphere evolution: emulation with neural networks
• The K2-ESPRINT Project VI: K2-105 b, a Hot-Neptune around a Metal-rich G-dwarf
• Effects of Planetesimal Accretion on the Thermal and Structural Evolution of Sub-Neptunes
• Unveiling the Planet Population at Birth
• The GAPS programme at TNG LXXI. A sub-Neptune suitable for atmospheric characterization in a multiplanet and mutually inclined system orbiting the bright K dwarf TOI-5789 (HIP 99452)
• Grain Growth in Escaping Atmospheres: Implications for the Radius Inflation of Super-Puffs