The extreme physical properties of the CoRoT-7b super-Earth

Research areas:

• Intérieurs planétaires (2011 - 2016)

Year:

2011

Authors:

• A. Leger
• Olivier Grasset
• B. Fegley
• F. Codron
• F. Albarede
• P. Barge
• R. Barnes
• Philippe Cance
• Sabrina Carpy
• F. Catalano
• C. Cavarroc
• O. Demangeon
• S. Ferraz-Mello
• P. Gabor
• J. -M. Griessmeier
• J. Leibacher
• G. Libourel
• A. -S. Maurin
• S. N. Raymond
• D. Rouan
• B. Samuel
• L. Schaefer
• J. Schneider
• P. A. Schuller
• F. Selsis
• Christophe Sotin

Journal:

ICARUS

Volume:

213

Number:

1

Pages:

1-11

Month:

May

ISSN:

0019-1035

BibTex:

@article{WOS:000290190100001, author = "A. Leger and Olivier Grasset and B. Fegley and F. Codron and F. Albarede and P. Barge and R. Barnes and Philippe Cance and Sabrina Carpy and F. Catalano and C. Cavarroc and O. Demangeon and S. Ferraz-Mello and P. Gabor and J. -M. Griessmeier and J. Leibacher and G. Libourel and A. -S. Maurin and S. N. Raymond and D. Rouan and B. Samuel and L. Schaefer and J. Schneider and P. A. Schuller and F. Selsis and Christophe Sotin", abstract = "The search for rocky exoplanets plays an important role in our quest for extra-terrestrial life. Here, we discuss the extreme physical properties possible for the first characterised rocky super-Earth, CoRoT-7b (R-pl = 1.58 +/- 0.10 R-Earth, M-pl = 6.9 +/- 1.2 M-Earth). It is extremely close to its star (a = 0.0171 AU = 4.48 R-st), with its spin and orbital rotation likely synchronised. The comparison of its location in the (M-pl, R-pl) plane with the predictions of planetary models for different compositions points to an Earth-like composition, even if the error bars of the measured quantities and the partial degeneracy of the models prevent a definitive conclusion. The proximity to its star provides an additional constraint on the model. It implies a high extreme-UV flux and particle wind, and the corresponding efficient erosion of the planetary atmosphere especially for volatile species including water. Consequently, we make the working hypothesis that the planet is rocky with no volatiles in its atmosphere, and derive the physical properties that result. As a consequence, the atmosphere is made of rocky vapours with a very low pressure (P ", doi = "10.1016/j.icarus.2011.02.004", extra = "PICL", issn = "0019-1035", journal = "ICARUS", month = "MAY", number = "1", pages = "1-11", title = "{T}he extreme physical properties of the {C}o{R}o{T}-7b super-{E}arth", volume = "213", year = "2011", }

Abstract:

The search for rocky exoplanets plays an important role in our quest for
extra-terrestrial life. Here, we discuss the extreme physical properties
possible for the first characterised rocky super-Earth, CoRoT-7b (R-pl =
1.58 +/- 0.10 R-Earth, M-pl = 6.9 +/- 1.2 M-Earth). It is extremely
close to its star (a = 0.0171 AU = 4.48 R-st), with its spin and orbital
rotation likely synchronised. The comparison of its location in the
(M-pl, R-pl) plane with the predictions of planetary models for
different compositions points to an Earth-like composition, even if the
error bars of the measured quantities and the partial degeneracy of the
models prevent a definitive conclusion. The proximity to its star
provides an additional constraint on the model. It implies a high
extreme-UV flux and particle wind, and the corresponding efficient
erosion of the planetary atmosphere especially for volatile species
including water. Consequently, we make the working hypothesis that the
planet is rocky with no volatiles in its atmosphere, and derive the
physical properties that result. As a consequence, the atmosphere is
made of rocky vapours with a very low pressure (P