The Roles of Tidal Evolution and Evaporative Mass Loss in the Origin of CoRoT-7 b

Abstract

CoRoT-7 b is the first confirmed rocky exoplanet, but, with an orbital semi-major axis of 0.0172 AU, its origins may be unlike any rocky planet in our solar system. In this study, we consider the roles of tidal evolution and evaporative mass loss in CoRoT-7 b's history, which together have modified the planet's mass and orbit. If CoRoT-7 b has always been a rocky body, evaporation may have driven off almost half its original mass, but the mass loss may depend sensitively on the extent of tidal decay of its orbit. As tides caused CoRoT-7 b's orbit to decay, they brought the planet closer to its host star, thereby enhancing the mass loss rate. Such a large mass loss also suggests the possibility that CoRoT-7 b began as a gas giant planet and had its original atmosphere completely evaporated. In this case, we find that CoRoT-7 b's original mass probably didn't exceed 200 Earth masses (about 2/3 of a Jupiter mass). Tides raised on the host star by the planet may have significantly reduced the orbital semi-major axis, perhaps causing the planet to migrate through mean-motion resonances with the other planet in the system, CoRoT-7 c. The coupling between tidal evolution and mass loss may be important not only for CoRoT-7 b but also for other close-in exoplanets, and future studies of mass loss and orbital evolution may provide insight into the origin and fate of close-in planets, both rocky and gaseous.

Accepted for publication by MNRAS on 2010 May 7

References in corpus (21)

• A super-Earth transiting a nearby low-mass star
• Atmospheric Escape from Hot Jupiters
• Transiting exoplanets from the CoRoT space mission VIII. CoRoT-7b: the first Super-Earth with measured radius
• Roche lobe effects on the atmospheric loss of "Hot Jupiters"
• Tidal Evolution of Close-in Extra-Solar Planets
• Detailed Models of super-Earths: How well can we infer bulk properties?
• On the tidal evolution of Hot Jupiters on inclined orbits
• Tidal friction in close-in satellites and exoplanets. The Darwin theory re-visited
• Three Possible Origins for the Gas Layer on GJ 1214b
• Ocean Planet or Thick Atmosphere: On the Mass-Radius Relationship for Solid Exoplanets with Massive Atmospheres
• Chemistry of Silicate Atmospheres of Evaporating Super-Earths
• WASP-19b: the shortest period transiting exoplanet yet discovered
• Energetic neutral atoms as the explanation for the high velocity hydrogen around HD 209458b
• Observable Consequences of Planet Formation Models in Systems with Close-in Terrestrial Planets
• Falling Transiting Extrasolar Giant Planets
• The Nature of the Atmosphere of the Transiting Super-Earth GJ 1214b
• Exoplanet HD209458b: inflated hydrogen atmosphere but no sign of evaporation
• Stability Limits in Extra-solar Planetary Systems
• CoRoT-7 b: Super-Earth or Super-Io?
• New Worlds on the Horizon: Earth-Sized Planets Close to Other Stars
• Tidal and Magnetic Interactions between a Hot Jupiter and its Host Star in the Magnetospheric Cavity of a Protoplanetary Disk

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• Planetary evaporation by UV & X-ray radiation: basic hydrodynamics
• How Thermal Evolution and Mass Loss Sculpt Populations of Super-Earths and Sub-Neptunes: Application to the Kepler-11 System and Beyond
• Radial velocity planets de-aliased. A new, short period for Super-Earth 55 Cnc e
• Super-Earth Atmospheres: Self-Consistent Gas Accretion and Retention
• Atmospheric Escape and the Evolution of Close-in Exoplanets
• The coronal X-ray - age relation and its implications for the evaporation of exoplanets
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• Born Dry in the Photo-Evaporation Desert: Kepler's Ultra-Short-Period Planets Formed Water-Poor
• The extreme physical properties of the CoRoT-7b super-Earth
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• Habitable Evaporated Cores: Transforming Mini-Neptunes into Super-Earths in the Habitable Zones of M Dwarfs
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• How formation time-scales affect the period dependence of the transition between rocky super-Earths and gaseous sub-Neptunes and implications for ${\eta }_{\oplus }$
• A grid of upper atmosphere models for 1--40 MEARTH planets: application to CoRoT-7 b and HD219134 b,c
• Vaporization of the Earth: Application to Exoplanet Atmospheres
• Heating efficiency in hydrogen-dominated upper atmospheres
• Mass-loss rates for transiting exoplanets
• Transit observations of the Hot Jupiter HD 189733b at X-ray wavelengths
• Probing the Blow-Off Criteria of Hydrogen-Rich "Super-Earths"
• Re-inflated Warm Jupiters Around Red Giants
• Factors Affecting the Radii of Close-in Transiting Exoplanets
• Mass-Loss Evolution of Close-In Exoplanets: Evaporation of Hot Jupiters and the Effect on Population
• Re-assessing the radial-velocity evidence for planets around CoRoT-7
• Deflating Super-Puffs: Impact of Photochemical Hazes on the Observed Mass-Radius Relationship of Low Mass Planets
• Tidally-driven Roche-Lobe Overflow of Hot Jupiters with MESA
• A comprehensive statistical assessment of star-planet interaction
• Climate instability on tidally locked exoplanets
• The sub-Neptune desert and its dependence on stellar type: Controlled by lifetime X-ray irradiation
• From Hot Jupiters to Super-Earths via Roche Lobe Overflow
• A Population of Very-Hot Super-Earths in Multiple-Planet Systems Should be Uncovered by Kepler
• The mass-period distribution of close-in exoplanets
• The XUV environments of exoplanets from Jupiter-size to super-Earth
• POET: A Model for (P)lanetary (O)rbital (E)volution due to (T)ides on Evolving Stars
• A Jovian planet in an eccentric 11.5 day orbit around HD1397 discovered by TESS
• The JADE code: Coupling secular exoplanetary dynamics and photo-evaporation
• A Survey for Very Short-Period Planets in the Kepler Data
• The high-energy environment in the super-earth system CoRoT-7
• Too Little, Too Late: How the Tidal Evolution of Hot Jupiters affects Transit Surveys of Clusters
• Evaporation of Jupiter like planets orbiting extreme horizontal branch stars
• Stars Get Dizzy After Lunch
• Atmospheric mass loss and evolution of short-period exoplanets: the examples of CoRoT-7b and Kepler-10b
• Super-Earths: A New Class of Planetary Bodies
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