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The Transit Ingress and the Tilted Orbit of the Extraordinarily Eccentric Exoplanet HD 80606b

Winn, Joshua N. and Howard, Andrew W. and Johnson, John Asher and Marcy, Geoffrey W. and Gazak, J. Zachary and Starkey, Donn and Ford, Eric B. and Colόn, Knicole D. and Reyes, Francisco and Nortmann, Lisa and Dreizler, Stefan and Odewahn, Stephen and Welsh, William F. and Kadakia, Shimonee and Vanderbei, Robert J. and Adams, Elisabeth R. and Lockhart, Matthew and Crossfield, Ian J. and Valenti, Jeff A. and Dantowitz, Ronald and Carter, Joshua A. (2009) The Transit Ingress and the Tilted Orbit of the Extraordinarily Eccentric Exoplanet HD 80606b. Astrophysical Journal, 703 (2). pp. 2091-2100. ISSN 0004-637X.

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We present the results of a transcontinental campaign to observe the 2009 June 5 transit of the exoplanet HD 80606b. We report the first detection of the transit ingress, revealing the transit duration to be 11.64 ± 0.25 hr and allowing more robust determinations of the system parameters. Keck spectra obtained at midtransit exhibit an anomalous blueshift, giving definitive evidence that the stellar spin axis and planetary orbital axis are misaligned. The Keck data show that the projected spin-orbit angle λ is between 32° and 87° with 68.3% confidence and between 14° and 142° with 99.73% confidence. Thus, the orbit of this planet is not only highly eccentric (e = 0.93) but is also tilted away from the equatorial plane of its parent star. A large tilt had been predicted, based on the idea that the planet's eccentric orbit was caused by the Kozai mechanism. Independently of the theory, it is worth noting that all three exoplanetary systems with known spin-orbit misalignments have massive planets on eccentric orbits, suggesting that those systems migrate through a different channel than lower mass planets on circular orbits.

Item Type:Article
Related URLs:
URLURL TypeDescription
Winn, Joshua N.0000-0002-4265-047X
Howard, Andrew W.0000-0001-8638-0320
Johnson, John Asher0000-0001-9808-7172
Marcy, Geoffrey W.0000-0002-2909-0113
Ford, Eric B.0000-0001-6545-639X
Welsh, William F.0000-0003-2381-5301
Crossfield, Ian J.0000-0002-1835-1891
Valenti, Jeff A.0000-0003-3305-6281
Additional Information:© 2009 American Astronomical Society. Received 2009 July 14; accepted 2009 August 19; published 2009 September 16. We thank Carly Chubak for measuring the heliocentric RV, Debra Fischer for help with measuring v sin i★, and Dan Fabrycky for interesting discussions about the Kozai mechanism. We thank Philip Choi, Jason Eastman, Mark Everett, Scott Gaudi, Zev Gurman, Marty Hidas,Matt Holman, and Alexander Rudy, for their willingness to join this campaign even though they were not able to participate due to weather or other factors. Mark Everett, Matt Holman, and Dave Latham also helped to gather the out-of-transit data from FLWO. We thank Bill Cochran and Ed Turner for help recruiting participants. We also thank Steve Fossey, Jonathan Irwin, and David Charbonneau for providing their data in a timely and convenient manner. We are grateful to Greg Laughlin, whose enthusiasm and persistence (and, it is suspected, a deal with the devil) led to the discovery of the eclipses of HD 80606. 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 the National Aeronautics and Space Administration, and wasmade possible by the generous financial support of the W.M.Keck Foundation. We extend special thanks to those of Hawaiian ancestry on whose sacred mountain of Mauna Kea we are privileged to be guests. Without their generous hospitality, the Keck and UH 2.2 m observations presented herein would not have been possible. The MONET network is funded by the Alfried Krupp von Bohlen und Halbach-Stiftung. W.F.W. and S.K. acknowledge support from NASA under grant NNX08AR14G issued through the Kepler Discovery Program. K.D.C., E.B.F., F.J.R., and observations from Rosemary Hill Observatory were supported by the University of Florida. Observations at Mt. Laguna Observatory were supported by the HPWREN network, funded by the National Science Foundation Grant Numbers 0087344 and 0426879 to University of California, San Diego. J.A.J. acknowledges support from an NSF Astronomy and Astrophysics Postdoctoral Fellowship (grant No. AST-0702821). Work by J.N.W. was supported by the NASA Origins program through awards NNX09AD36G and NNX09AB33G. J.N.W. also gratefully acknowledges the support of the MIT Class of 1942 Career Development Professorship. Facilities: Keck I (HIRES) FLWO:1.2 m (Keplercam), UH:2.2 m (OPTIC), McD:0.8 m
Funding AgencyGrant Number
W. M. Keck FoundationUNSPECIFIED
Alfried Krupp von Bohlen und Halbach-StiftungUNSPECIFIED
University of FloridaUNSPECIFIED
NSF Astronomy and Astrophysics FellowshipAST-0702821
MIT Class of 1942 Career Development ProfessorshipUNSPECIFIED
Subject Keywords:planetary systems; planetary systems: formation; stars: individual (HD 80606); stars: rotation
Issue or Number:2
Record Number:CaltechAUTHORS:20130114-095304108
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Official Citation:The Transit Ingress and the Tilted Orbit of the Extraordinarily Eccentric Exoplanet HD 80606b Joshua N. Winn et al. 2009 ApJ 703 2091
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:36346
Deposited By: Ruth Sustaita
Deposited On:14 Jan 2013 18:40
Last Modified:09 Mar 2020 13:19

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