Origin and Loss of nebula-captured hydrogen envelopes from "sub"- to "super-Earths" in the habitable zone of Sun-like stars

Abstract

We investigate the origin and loss of captured hydrogen envelopes from protoplanets between `sub-Earth'-like bodies of 0.1$M_{\oplus }$ up to `super-Earths' with 5$M_{\oplus }$ in the HZ of a Sun like G star, assuming their rocky cores had formed before the nebula dissipated. We model the gravitational accumulation of nebula gas around a core as a function of protoplanetary luminosity during accretion and calculate the resulting surface temperature by solving the hydrostatic structure equations for the protoplanetary nebula. Depending on nebular properties and resulting luminosities, for planetary bodies of 0.1--1$M_{\oplus }$ we obtain hydrogen envelopes with masses between $\sim 2.5\times 10^{19}$--$1.5\times 10^{26}$ g. For `super-Earths' with masses between 2--5$M_{\oplus }$ hydrogen envelopes within the mass range of $\sim 7.5\times 10^{23}$--$1.5\times 10^{28}$ g can be captured. To study the escape of these hydrogen-dominated protoatmospheres, we apply a hydrodynamic upper atmosphere model and calculate the loss rates due to the heating by the high XUV flux of the young star. Our results indicate that under most nebula conditions `sub-Earth' and Earth-mass planets can lose their envelopes by thermal escape during the first $100$ Myr after the disk dissipated. However, if a nebula has a low dust depletion factor or low accretion rates resulting in low protoplanetary luminosities, it is possible that even protoplanets with Earth-mass cores may keep their hydrogen envelopes during their whole lifetime. In contrast to lower mass protoplanets, `super-Earths' accumulate a huge amount of nebula gas and lose only tiny fractions of their primordial envelopes. Our results agree with the fact that Venus, Earth, and Mars are not surrounded by dense hydrogen envelopes, as well as with the recent discoveries of low density `super-Earths' that most likely could not get rid of their protoatmospheres.

17 pages, 5 figures, accepted to MNRAS

References in corpus (5)

• Line and Mean Opacities for Ultracool Dwarfs and Extrasolar Planets
• Kepler-62: A five-planet system with planets of 1.4 and 1.6 Earth radii in the Habitable Zone
• Constraints on the mass of a habitable planet with water of nebular origin
• Probing the Blow-Off Criteria of Hydrogen-Rich "Super-Earths"
• An Independent Planet Search In The Kepler Dataset. II. An extremely low-density super-Earth mass planet around Kepler-87

Cited by in corpus (77)

• Extreme Water Loss and Abiotic O${}_2$ Buildup On Planets Throughout the Habitable Zones of M Dwarfs
• Planetary population synthesis coupled with atmospheric escape: a statistical view of evaporation
• Atmospheric Escape and the Evolution of Close-in Exoplanets
• The Extreme Ultraviolet and X-Ray Sun in Time: High-Energy Evolutionary Tracks of a Solar-Like Star
• Stellar Winds on the Main-Sequence II: the Evolution of Rotation and Winds
• The cosmic shoreline: the evidence that escape determines which planets have atmospheres, and what this may mean for Proxima Centauri b
• Exoplanetary Atmospheres - Chemistry, Formation Conditions, and Habitability
• On the formation of planetary systems via oligarchic growth in thermally evolving viscous discs
• Habitable Evaporated Cores: Transforming Mini-Neptunes into Super-Earths in the Habitable Zones of M Dwarfs
• Zodiacal Exoplanets In Time (ZEIT) I: A Neptune-sized planet orbiting an M4.5 dwarf in the Hyades Star Cluster
• How formation time-scales affect the period dependence of the transition between rocky super-Earths and gaseous sub-Neptunes and implications for ${\eta }_{\oplus }$
• The Evolution of Stellar Rotation and the hydrogen atmospheres of habitable-zone Terrestrial Planets
• Heating efficiency in hydrogen-dominated upper atmospheres
• Earth shaped by primordial H${}_2$ atmospheres
• Habitability of Terrestrial-Mass Planets in the HZ of M Dwarfs. I. H/He-Dominated Atmospheres
• The quest for stellar coronal mass ejections in late-type stars: I. Investigating Balmer-line asymmetries of single stars in Virtual Observatory data
• Stellar Winds on the Main-Sequence I: Wind Model
• Atmospheric Regimes and Trends on Exoplanets and Brown Dwarfs
• The Upper Atmospheres of Terrestrial Planets: Carbon Dioxide Cooling and the Earth's Thermospheric Evolution
• Atmosphere expansion and mass loss of close-orbit giant exoplanets heated by stellar XUV: I. Modeling of hydrodynamic escape of upper atmospheric material
• Stellar Coronal Mass Ejections I. Estimating occurrence frequencies and mass-loss rates
• Thermal mass loss of protoplanetary cores with hydrogen-dominated atmospheres: The influences of ionization and orbital distance
• On the formation of compact planetary systems via concurrent core accretion and migration
• EUV irradiation of exoplanet atmospheres occurs on Gyr timescales
• Identifying the "true" radius of the hot sub-Neptune CoRoT-24b by mass loss modelling
• A new perspective on interiors of ice-rich planets: Ice-rock mixture instead of ice on top of rock
• Hydrogen dominated atmospheres on terrestrial mass planets: evidence, origin and evolution
• The Role of N2 as a Geo-Biosignature for the Detection and Characterization of Earth-like Habitats
• Escape and fractionation of volatiles and noble gases from Mars-sized planetary embryos and growing protoplanets
• Hydrodynamic simulations of captured protoatmospheres around Earth-like planets
• K2-106, a system containing a metal-rich planet and a planet of lower density
• High-resolution spectroscopy of flares and CMES on AD Leo*
• Convective outgassing efficiency in planetary magma oceans: insights from computational fluid dynamics
• Extreme hydrodynamic atmospheric loss near the critical thermal escape regime
• Loss and fractionation of noble gas isotopes and moderately volatile elements from planetary embryos and early Venus, Earth and Mars
• Susceptibility of planetary atmospheres to mass loss and growth by planetesimal impacts: the impact shoreline
• Growth and evolution of secondary volcanic atmospheres: I. Identifying the geological character of hot rocky planets
• Solar XUV and ENA-driven water loss from early Venus' steam atmosphere
• Formation of Venus, Earth and Mars: Constrained by isotopes
• Growing Mars fast: High-resolution GPU simulations of embryo formation
• Identifiable Acetylene Features Predicted for Young Earth-like Exoplanets with Reducing Atmospheres undergoing Heavy Bombardment
• Habitable Evaporated Cores and the Occurrence of Panspermia near the Galactic Center
• TOI-1468: A system of two transiting planets, a super-Earth and a mini-Neptune, on opposite sides of the radius valley
• Origin and Stability of Exomoon Atmospheres - Implications for Habitability
• Geoscience for understanding habitability in the solar system and beyond
• Stellar Flares versus Luminosity: XUV-induced Atmospheric Escape and Planetary Habitability
• Evolution of X-ray Activity in <25 Myr Old Pre-Main Sequence Stars
• Potential long-term habitable conditions on planets with primordial H-He atmospheres
• Transit Ly-$\alpha$ signatures of terrestrial planets in the habitable zones of M dwarfs
• Losing Oceans: The Effects of Composition on the Thermal Component of Impact-driven Atmospheric Loss
• Importance of Sample Selection in Exoplanet Atmosphere Population Studies
• Suppression of hydrodynamic escape of an H2-rich early Earth atmosphere by radiative cooling of carbon oxides
• Escape and evolution of Titan's N${}_2$ atmosphere constrained by ${}^{14}$N/${}^{15}$N isotope ratios
• Redox state and interior structure control on the long-term habitability of stagnant-lid planets
• Modification of the radioactive heat budget of Earth-like exoplanets by the loss of primordial atmospheres
• Finding the UV-Visible Path Forward: Proceedings of the Community Workshop to Plan the Future of UV/Visible Space Astrophysics
• Colliding Winds in Low-Mass Binary Star Systems: wind interactions and implications for habitable planets
• Limitation of atmospheric composition by combustion-explosion in exoplanetary atmospheres
• Non-detection of Helium in the Hot Jupiter WASP-48b
• Photometric observations of flares on AD Leo from GWAC-F30 and TESS
• The Dynamic Proto-atmospheres around Low-Mass Planets with Eccentric Orbits
• Stellar activity and planetary atmosphere evolution in tight binary star systems
• Self-Shielding Enhanced Organics Synthesis in an Early Reduced Earth's Atmosphere
• Stellar wind impact on early atmospheres around unmagnetized Earth-like planets
• A Hot Saturn Near (but unassociated with) the Open Cluster NGC 1817
• The Flare-Activity of 2MASSJ16111534-1757214 in the Upper Scorpius association
• Revisiting the Planet Mass and Stellar Metallicity Relation for Low-Mass Exoplanets Orbiting GKM Class Stars
• Evolution of Earth-like extended exospheres orbiting solar-like stars
• The Dynamical Viability of an Extended Jupiter Ring System
• Comparative Analysis of the Model for Exoplanet Atmosphere Outflow
• Evolution and Observable Properties of Rocky Planet Atmospheres
• Atmosphere Loss by Aerial Bursts
• UV lines as a tracers for the XUV-fluxes of stars and the PLATOspec project
• Survival of Primordial Planetary Atmospheres: Mass Loss from Temperate Terrestrial Planets
• The formation of planetary systems with SPICA
• ExoplANETS-A: A VO database for host stars and planetary systems: The effect of XUV on planet atmospheres
• A Multi-Planet System's Sole Super-Puff: Exploring Allowable Physical Parameters for the Cold Super-Puff HIP 41378 f