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Discovery and Rossiter-Mclaughlin Effect of Exoplanet Kepler-8b

Jenkins, Jon M. and Gautier, Thomas N., III and Johnson, John Asher and Howard, Andrew W. (2010) Discovery and Rossiter-Mclaughlin Effect of Exoplanet Kepler-8b. Astrophysical Journal, 724 (2). pp. 1108-1119. ISSN 0004-637X.

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We report on the discovery and the Rossiter-McLaughlin (R-M) effect of Kepler-8b, a transiting planet identified by the NASA Kepler Mission. Kepler photometry and Keck-HIRES radial velocities yield the radius and mass of the planet around this F8IV subgiant host star. The planet has a radius R_P = 1.419 R_J and a mass M_P = 0.60 M_J, yielding a density of 0.26 g cm^(–3), one of the lowest planetary densities known. The orbital period is P = 3.523 days and the orbital semimajor axis is 0.0483^(+0.0006) _(–0.0012) AU. The star has a large rotational vsin i of 10.5 ± 0.7 km s^(–1) and is relatively faint (V ≈ 13.89 mag); both properties are deleterious to precise Doppler measurements. The velocities are indeed noisy, with scatter of 30 m s^(–1), but exhibit a period and phase that are consistent with those implied by transit photometry. We securely detect the R-M effect, confirming the planet's existence and establishing its orbit as prograde. We measure an inclination between the projected planetary orbital axis and the projected stellar rotation axis of λ = –26º.4 ± 10º.1, indicating a significant inclination of the planetary orbit. R-M measurements of a large sample of transiting planets from Kepler will provide a statistically robust measure of the true distribution of spin-orbit orientations for hot Jupiters around F and early G stars.

Item Type:Article
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Jenkins, Jon M.0000-0002-4715-9460
Johnson, John Asher0000-0001-9808-7172
Howard, Andrew W.0000-0001-8638-0320
Additional Information:© 2010 American Astronomical Society. Received 2010 February 14; accepted 2010 September 2; published 2010 November 11. Based in part on observations obtained at the W. M. Keck Observatory, which is operated as a scientific partnership between the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. Funding for this mission is provided by NASA’s Science Mission Directorate. Many people have contributed to the success of the Kepler Mission, and it is impossible to acknowledge them all. Valuable advice and assistance were provided by Willie Torres, Riley Duren, M. Crane, D. Ciardi, and Josh Winn. Special technical help was provided by Carly Chubak, G. Mandushev, and Josh Winn. We thank E. Bachtel and his team at Ball Aerospace for their work on the Kepler photometer and R. Thompson for key contributions to engineering, and C. Botosh for able management. G.W.M. thanks and acknowledges support from NASA Cooperative Agreement NNX06AH52G. Facility: Kepler.
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Subject Keywords:radio lines: planetary systems; stars: fundamental parameters; stars: individual (Kepler-8, KIC 6822244, 2MASS 18450914+4227038)
Issue or Number:2
Record Number:CaltechAUTHORS:20130108-080503265
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Official Citation:Discovery and Rossiter-Mclaughlin Effect of Exoplanet Kepler-8b Jon M. Jenkins et al. 2010 ApJ 724 1108
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:36224
Deposited By: Ruth Sustaita
Deposited On:08 Jan 2013 16:41
Last Modified:09 Mar 2020 13:18

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