Winn, Joshua N. and Fabrycky, Daniel and Albrecht, Simon and Johnson, John Asher (2010) Hot Stars with Hot Jupiters Have High Obliquities. Astrophysical Journal Letters, 718 (2). L145-L149. ISSN 0004-637X http://resolver.caltech.edu/CaltechAUTHORS:20100830-135040266
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We show that stars with transiting planets for which the stellar obliquity is large are preferentially hot (T_(eff) > 6250 K). This could explain why small obliquities were observed in the earliest measurements, which focused on relatively cool stars drawn from Doppler surveys, as opposed to hotter stars that emerged more recently from transit surveys. The observed trend could be due to differences in planet formation and migration around stars of varying mass. Alternatively, we speculate that hot-Jupiter systems begin with a wide range of obliquities, but the photospheres of cool stars realign with the orbits due to tidal dissipation in their convective zones, while hot stars cannot realign because of their thinner convective zones. This in turn would suggest that hot Jupiters originate from few-body gravitational dynamics and that disk migration plays at most a supporting role.
|Additional Information:||© 2010 American Astronomical Society. Received 2010 May 3; accepted 2010 June 29; published 2010 July 12. We thank Jeremy Goodman, Matija Cuk, Bill Cochran, Sally Dodson-Robinson, Andrew Howard, Geoff Marcy, Tim Morton, Fred Rasio, Dimitar Sasselov, and Richard Wade for helpful discussions. J.N.W. gratefully acknowledges support from the NASA Origins program through award NNX09AD36G and the MIT Class of 1942, as well as the Tinsley Scholars program and the hospitality of the Astronomy Department at the University of Texas, Austin. D.F. acknowledges support from the Michelson Fellowship, supported by the National Aeronautics and Space Administration and administered by the Michelson Science Center. S. Albrecht acknowledges support from an NWO Rubicon fellowship.|
|Subject Keywords:||planetary systems; planets and satellites: formation; planet–star interactions; stars: rotation|
|Classification Code:||PACS: 97.82.-j; 97.10.Kc; 97.10.Ri; 97.20.-w; 97.10.Ex|
|Official Citation:||Joshua N. Winn et al 2010 ApJ 718 L145 doi: 10.1088/2041-8205/718/2/L145|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Jason Perez|
|Deposited On:||03 Sep 2010 20:56|
|Last Modified:||26 Dec 2012 12:22|
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