Bibcode
Hatzes, Artie P.; Fridlund, Malcolm; Nachmani, Gil; Mazeh, Tsevi; Valencia, Diana; Hébrard, Guillaume; Carone, Ludmila; Pätzold, Martin; Udry, Stephane; Bouchy, Francois; Deleuil, Magali; Moutou, Claire; Barge, Pierre; Bordé, Pascal; Deeg, H. J.; Tingley, B.; Dvorak, Rudolf; Gandolfi, Davide; Ferraz-Mello, Sylvio; Wuchterl, Günther; Guenther, Eike; Guillot, Tristan; Rauer, Heike; Erikson, Anders; Cabrera, Juan; Csizmadia, Szilard; Léger, Alain; Lammer, Helmut; Weingrill, Jörg; Queloz, Didier; Alonso, Roi; Rouan, Daniel; Schneider, Jean
Bibliographical reference
The Astrophysical Journal, Volume 743, Issue 1, article id. 75 (2011).
Advertised on:
12
2011
Journal
Citations
104
Refereed citations
92
Description
The mass of CoRoT-7b, the first transiting super-Earth exoplanet, is
still a subject of debate. A wide range of masses have been reported in
the literature ranging from as high as 8 M ⊕ to as low
as 2.3 M ⊕. This range in mass is largely due to the
activity level of the star that contributes a significant amount of
radial velocity (RV) "jitter" and how the various methods correct this
jitter. Although most mass determinations give a density consistent with
a rocky planet, the lower value permits a bulk composition that can be
up to 50% water. We present an analysis of the CoRoT-7b RV measurements
that uses very few and simple assumptions in treating the activity
signal. By analyzing those RV data for which multiple measurements were
made in a given night, we remove the activity related RV contribution
without any a priori model. We argue that the contribution of activity
to the final RV curve is negligible and that the K-amplitude due to the
planet is well constrained. This yields a mass of 7.42 ± 1.21 M
⊕ and a mean density of ρ = 10.4 ± 1.8 gm
cm-3. CoRoT-7b is similar in mass and radius to the
second rocky planet to be discovered, Kepler-10b, and within the errors
they have identical bulk densities—they are virtual twins. These
bulk densities lie close to the density-radius relationship for
terrestrial planets similar to what is seen for Mercury. CoRoT-7b and
Kepler-10b may have an internal structure more like Mercury than the
Earth.
Related projects
Helio and Astero-Seismology and Exoplanets Search
The principal objectives of this project are: 1) to study the structure and dynamics of the solar interior, 2) to extend this study to other stars, 3) to search for extrasolar planets using photometric methods (primarily by transits of their host stars) and their characterization (using radial velocity information) and 4) the study of the planetary
Savita
Mathur