A Caltech Library Service

Kepler-10 c: a 2.2 Earth Radius Transiting Planet in a Multiple System

Fressin, François and Ciardi, David R. and Koch, David G. (2011) Kepler-10 c: a 2.2 Earth Radius Transiting Planet in a Multiple System. Astrophysical Journal Supplement Series, 197 (1). Art. No. 5. ISSN 0067-0049.

PDF - Published Version
See Usage Policy.


Use this Persistent URL to link to this item:


The Kepler mission has recently announced the discovery of Kepler-10 b, the smallest exoplanet discovered to date and the first rocky planet found by the spacecraft. A second, 45 day period transit-like signal present in the photometry from the first eight months of data could not be confirmed as being caused by a planet at the time of that announcement. Here we apply the light curve modeling technique known as BLENDER to explore the possibility that the signal might be due to an astrophysical false positive (blend). To aid in this analysis we report the observation of two transits with the Spitzer Space Telescope at 4.5 μm. When combined, they yield a transit depth of 344 ± 85 ppm that is consistent with the depth in the Kepler passband (376 ± 9 ppm, ignoring limb darkening), which rules out blends with an eclipsing binary of a significantly different color than the target. Using these observations along with other constraints from high-resolution imaging and spectroscopy, we are able to exclude the vast majority of possible false positives. We assess the likelihood of the remaining blends, and arrive conservatively at a false alarm rate of 1.6 × 10^(–5) that is small enough to validate the candidate as a planet (designated Kepler-10 c) with a very high level of confidence. The radius of this object is measured to be R_p = 2.227^(+0.052)_(–0.057) R_⊕ (in which the error includes the uncertainty in the stellar properties), but currently available radial-velocity measurements only place an upper limit on its mass of about 20 M_⊕. Kepler-10 c represents another example (with Kepler-9 d and Kepler-11 g) of statistical "validation" of a transiting exoplanet, as opposed to the usual "confirmation" that can take place when the Doppler signal is detected or transit timing variations are measured. It is anticipated that many of Kepler's smaller candidates will receive a similar treatment since dynamical confirmation may be difficult or impractical with the sensitivity of current instrumentation.

Item Type:Article
Related URLs:
URLURL TypeDescription
Ciardi, David R.0000-0002-5741-3047
Additional Information:© 2011 The American Astronomical Society. Received 2011 April 9; accepted 2011 April 30; published 2011 October 10. Funding for this Discovery mission is provided by NASA’s Science Mission Directorate. This research has made use of the facilities at the NASA Advanced Supercomputing Division (NASA Ames Research Center), and is based also on observations made with the Spitzer Space Telescope which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. Support for this work was provided by NASA through an award issued by JPL/Caltech. We thank Mukremin Kilic and Rosanne Di Stefano for helpful discussions about white dwarfs, and the anonymous referee for constructive comments. Facilities: Kepler, Spitzer,Keck:I (HIRES), Hale,WIYN:0.9m
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
Subject Keywords:binaries: eclipsing; planetary systems; stars: individual (Kepler-10, KOI-072, KIC 11904151); stars: statistics
Issue or Number:1
Record Number:CaltechAUTHORS:20111214-101753556
Persistent URL:
Official Citation:Kepler-10 c: a 2.2 Earth Radius Transiting Planet in a Multiple System François Fressin et al. 2011 ApJS 197 5
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:28464
Deposited By: Ruth Sustaita
Deposited On:14 Dec 2011 19:14
Last Modified:03 Oct 2019 03:32

Repository Staff Only: item control page