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The Neptune-sized Circumbinary Planet Kepler-38b

Orosz, Jerome A. and Shporer, Avi (2012) The Neptune-sized Circumbinary Planet Kepler-38b. Astrophysical Journal, 758 (2). Art. No. 87. ISSN 0004-637X.

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We discuss the discovery and characterization of the circumbinary planet Kepler-38b. The stellar binary is single-lined, with a period of 18.8 days, and consists of a moderately evolved main-sequence star (M_A = 0.949 ± 0.059 M_☉ and R_A = 1.757 ± 0.034 R_☉) paired with a low-mass star (M_B = 0.249 ± 0.010 M_☉ and R_B = 0.2724 ± 0.0053 R_☉) in a mildly eccentric (e = 0.103) orbit. A total of eight transits due to a circumbinary planet crossing the primary star were identified in the Kepler light curve (using Kepler Quarters 1-11), from which a planetary period of 105.595 ± 0.053 days can be established. A photometric dynamical model fit to the radial velocity curve and Kepler light curve yields a planetary radius of 4.35 ± 0.11 R_⊕, or equivalently 1.12 ± 0.03 R_(Nep). Since the planet is not sufficiently massive to observably alter the orbit of the binary from Keplerian motion, we can only place an upper limit on the mass of the planet of 122 M_⊕ (7.11 M_(Nep) or equivalently 0.384 M_(Jup)) at 95% confidence. This upper limit should decrease as more Kepler data become available.

Item Type:Article
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Orosz, Jerome A.0000-0001-9647-2886
Shporer, Avi0000-0002-1836-3120
Additional Information:© 2012 American Astronomical Society. Received 2012 July 6; accepted 2012 August 17; published 2012 October 3. Based on observations obtained with the Hobby-Eberly Telescope, which is a joint project of the University of Texas at Austin, the Pennsylvania State University, Stanford University, Ludwig-Maximilians-Universität München, and Georg-August-Universität Göttingen. Kepler was selected as the 10th mission of the Discovery Program. Funding for this mission is provided by NASA, Science Mission Directorate. J.A.O. and W.F.W. acknowledge support from the Kepler Participating Scientist Program via NASA Grant NNX12AD23G. Support was also provided by the National Science Foundation via grants AST-1109928 to J.A.O., W.F.W., and G.W., AST-0908642 to R.W., AST-0645416 to E.A., and AST-1007992 to G.T.
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Subject Keywords: binaries: eclipsing; planets and satellites: detection; planets and satellites: fundamental parameters; planets and satellites: individual (Kepler-38b); stars: fundamental parameters
Issue or Number:2
Record Number:CaltechAUTHORS:20121210-092140619
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Official Citation:The Neptune-sized Circumbinary Planet Kepler-38b Jerome A. Orosz et al. 2012 ApJ 758 87
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:35891
Deposited By: Ruth Sustaita
Deposited On:10 Dec 2012 17:59
Last Modified:09 Mar 2020 13:19

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