Confirmation of a Retrograde Orbit for Exoplanet Wasp-17b
Author(s)
Bayliss, Daniel D. R.; Winn, Joshua Nathan; Mardling, Rosemary A.; Sackett, Penny D.
DownloadWinn6.pdf (520.3Kb)
OPEN_ACCESS_POLICY
Open Access Policy
Creative Commons Attribution-Noncommercial-Share Alike
Terms of use
Metadata
Show full item recordAbstract
We present high-precision radial velocity observations of WASP-17 throughout the transit of its close-in giant planet, using the MIKE spectrograph on the 6.5 m Magellan Telescope at Las Campanas Observatory. By modeling the Rossiter-McLaughlin effect, we find the sky-projected spin-orbit angle to be [lambda] = 167.4 ± 11.2 deg. This independently confirms the previous finding that WASP-17b is on a retrograde orbit, suggesting it underwent migration via a mechanism other than just the gravitational interaction between the planet and the disk. Interestingly, our result for [lambda] differs by 45 ± 13 deg from the previously announced value, and we also find that the spectroscopic transit occurs 15 ± 5 minutes earlier than expected, based on the published ephemeris. The discrepancy in the ephemeris highlights the need for contemporaneous spectroscopic and photometric transit observations whenever possible.
Date issued
2010-10Department
Massachusetts Institute of Technology. Department of Physics; MIT Kavli Institute for Astrophysics and Space ResearchJournal
Astrophysical Journal Letters
Publisher
Institute of Physics
Citation
Bayliss, Daniel D. R. et al. "Confirmation of a Retrograde Orbit for Exoplanet Wasp-17b." 2010 ApJ 722.2 L224-L227
Version: Author's final manuscript
ISSN
2041-8205
2041-8213