Validation of Small Kepler Transiting Planet Candidates in or near the Habitable Zone
- Creators
- Torres, Guillermo
- Kane, Stephen R.
- Rowe, Jason F.
- Batalha, Natalie M.
- Henze, Christopher E.
- Ciardi, David R.
- Barclay, Thomas
- Borucki, William J.
- Buchhave, Lars A.
- Crepp, Justin R.
- Everett, Mark E.
- Horch, Elliott P.
- Howard, Andrew W.
- Howell, Steve B.
- Isaacson, Howard T.
- Jenkins, Jon M.
- Latham, David W.
- Petigura, Erik A.
- Quintana, Elisa V.
Abstract
A main goal of NASA's Kepler Mission is to establish the frequency of potentially habitable Earth-size planets (η⊕). Relatively few such candidates identified by the mission can be confirmed to be rocky via dynamical measurement of their mass. Here we report an effort to validate 18 of them statistically using the BLENDER technique, by showing that the likelihood they are true planets is far greater than that of a false positive. Our analysis incorporates follow-up observations including high-resolution optical and near-infrared spectroscopy, high-resolution imaging, and information from the analysis of the flux centroids of the Kepler observations themselves. Although many of these candidates have been previously validated by others, the confidence levels reported typically ignore the possibility that the planet may transit a star different from the target along the same line of sight. If that were the case, a planet that appears small enough to be rocky may actually be considerably larger and therefore less interesting from the point of view of habitability. We take this into consideration here and are able to validate 15 of our candidates at a 99.73% (3σ) significance level or higher, and the other three at a slightly lower confidence. We characterize the GKM host stars using available ground-based observations and provide updated parameters for the planets, with sizes between 0.8 and 2.9 R⊕. Seven of them (KOI-0438.02, 0463.01, 2418.01, 2626.01, 3282.01, 4036.01, and 5856.01) have a better than 50% chance of being smaller than 2 R⊕ and being in the habitable zone of their host stars.
Additional Information
© 2017 The American Astronomical Society. Received 2017 August 11; revised 2017 November 1; accepted 2017 November 1; published 2017 December 1. We thank the anonymous referee for helpful comments on the original manuscript. This paper includes data collected by the Kepler spacecraft. Funding for the Kepler Mission is provided by NASA's Science Mission Directorate. Resources supporting this work were provided by the NASA High-End Computing (HEC) Program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center. The research has also made use of NASA's Astrophysics Data System (ADS) and of data products from the Mikulski Archive for Space Telescopes (MAST). Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA. We extend special thanks to those of Hawaiian ancestry on whose sacred mountain of Maunakea we are privileged to be guests. G.T. acknowledges partial support for this work from NASA grant NNX14AB83G (Kepler Participating Scientist Program) and Cooperative Agreement NNX13AB58A with the Smithsonian Astrophysical Observatory (PI: D.W.L.). This research was enabled in part by support provided by Calcul Québec (http://www.calculquebec.ca) and Compute Canada (http://www.computecanada.ca).Attached Files
Published - Torres_2017_AJ_154_264.pdf
Submitted - 1711.01267.pdf
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Additional details
- Eprint ID
- 83597
- Resolver ID
- CaltechAUTHORS:20171130-103943491
- NNX14AB83G
- NASA
- NNX13AB58A
- NASA
- Calcul Québec
- Compute Canada
- Created
-
2017-11-30Created from EPrint's datestamp field
- Updated
-
2021-11-15Created from EPrint's last_modified field
- Caltech groups
- Astronomy Department