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The Roles of Tidal Evolution and Evaporative Mass Loss in the Origin of CoRoT-7 bCoRoT-7 b is the first confirmed rocky exoplanet, but, with an orbital semimajor 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 did not exceed 200 Earth masses (about two-third of a Jupiter mass). Tides raised on the host star by the planet may have significantly reduced the orbital semimajor 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.
Document ID
20110013468
Document Type
Reprint (Version printed in journal)
Authors
Jackson, Brian (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Miller, Neil (California Univ. Santa Cruz, CA, United States)
Barnes, Rory (Washington Univ. Seattle, WA, United States)
Raymond, Sean N. (Bordeaux 2 Univ. France)
Fortney, Jonathan J. (California Univ. Santa Cruz, CA, United States)
Greenberg, Richard (Arizona Univ. Tucson, AZ, United States)
Date Acquired
August 25, 2013
Publication Date
February 21, 2010
Publication Information
Publication: Monthly Notices of the Royal Astronomical Society
Volume: 407
Issue: 2
Subject Category
Lunar and Planetary Science and Exploration
Report/Patent Number
GSFC.JA.4464.2011
Funding Number(s)
CONTRACT_GRANT: NNH05ZDA001C
CONTRACT_GRANT: NNG05GH65G
Distribution Limits
Public
Copyright
Other