Improved Measurement of the Rossiter-McLaughlin Effect in the Exoplanetary System HD 17156

We present an improved measurement of the Rossiter-McLaughlin effect for the exoplanetary system HD 17156, based on radial-velocity data gathered with the Subaru 8.2m telescope throughout the planetary transit of UT 2008 November 7. The data allow for a precise and independent determination of the p...

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Bibliographic Details
Main Authors: Winn, Joshua Nathan, Narita, Norio, Hirano, Teruyuki, Sato, Bunei, Suto, Yasushi, Turner, Edwin L., Aoki, Wako, Tamura, Motohide, Yamada, Toru
Other Authors: Massachusetts Institute of Technology. Department of Physics
Format: Article
Language:en_US
Published: Astronomical Society of Japan 2013
Online Access:http://hdl.handle.net/1721.1/76743
https://orcid.org/0000-0002-4265-047X
Description
Summary:We present an improved measurement of the Rossiter-McLaughlin effect for the exoplanetary system HD 17156, based on radial-velocity data gathered with the Subaru 8.2m telescope throughout the planetary transit of UT 2008 November 7. The data allow for a precise and independent determination of the projected spin-orbit angle of this system: λ = 10[° over .]0 ± 5[° over .]1. This result supersedes the previous claim of λ = 62° ± 25° by Narita et al., which was based on lower-precision data with poor statistics. Thus the stellar spin and planetary orbital axes of the HD 17156 system are likely to be well-aligned, despite the planet's large orbital eccentricity suggesting a history of strong dynamical interactions.