The Rossiter–McLaughlin Effect of the Transiting Exoplanet XO-4b
Autor: | Matthew J. Holman, Roberto Sanchis-Ojeda, Wako Aoki, Motohide Tamura, Teruyuki Hirano, Bun'ei Sato, Joshua N. Winn, Norio Narita |
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Přispěvatelé: | Massachusetts Institute of Technology. Department of Physics, MIT Kavli Institute for Astrophysics and Space Research, Winn, Joshua Nathan, Sanchis Ojeda, Roberto, Hirano, Teruyuki |
Rok vydání: | 2010 |
Předmět: |
Earth and Planetary Astrophysics (astro-ph.EP)
Physics Rossiter–McLaughlin effect FOS: Physical sciences Astronomy Astronomy and Astrophysics Planetary system Light curve Exoplanet law.invention Radial velocity Telescope Space and Planetary Science law Astrophysics::Solar and Stellar Astrophysics Astrophysics::Earth and Planetary Astrophysics Transit (astronomy) Subaru Telescope Astrophysics::Galaxy Astrophysics Astrophysics - Earth and Planetary Astrophysics |
Zdroj: | Prof. Winn via Mat Willmott |
ISSN: | 2053-051X 0004-6264 |
Popis: | We report photometric and radial velocity observations of the XO-4 transiting planetary system, conducted with the FLWO 1.2 m telescope and the 8.2 m Subaru Telescope. Based on the new light curves, the refined transit ephemeris of XO-4b is $P$ $=$ 4.1250828$\ \pm\ $0.0000040 d and $T_{\rm c}$ [BJD$_{\rm TDB}$] $=$ 2454485.93323$\ \pm\ $0.00039. We measured the Rossiter–McLaughlin effect of XO-4b and estimated the sky-projected angle between the stellar spin axis and the planetary orbital axis to be $\lambda$ $=$ $-$46$^\circ\!\!\!.$7 $\ ^{{+8^\circ\!\!\!.1}}_{{\ -6^\circ\!\!\!.1}}$. This measurement of $\lambda$ is less robust than in some other cases because the impact parameter of the transit is small, causing a strong degeneracy between $\lambda$ and the projected stellar rotational velocity. Nevertheless, our finding of a spin–orbit misalignment suggests that the migration process for XO-4b involved few-body dynamics rather than interaction with a gaseous disk. In addition, our result conforms with the pattern reported by Winn et al. (2010, ApJ, 718, L145) that high obliquities are preferentially found for stars with effective temperatures hotter than 6250 K. Japan Society for the Promotion of Science (Fellowship for Research DC1: 22-5935) Japan Society for the Promotion of Science (Fellowship for Research PD: 20-8141) United States. National Aeronautics and Space Administration (Origins program grant NNX09AD36G) United States. National Aeronautics and Space Administration (Origins program grant NNX09AB33G) |
Databáze: | OpenAIRE |
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