| タイトル | HAT-P-7: A Retrograde or Polar Orbit, and a Third Body |
| 著者（英） | Holman, Matthew J.; Howard, Andrew W.; Winn, Joshua N.; Crossfield, Ian J.; Albrecht, Simon; Johnson, John Asher; Marcy, Geoffrey W. |
| 著者所属（英） | Massachusetts Inst. of Tech. |
| 発行日 | 2009-10-01 |
| 言語 | eng |
| 内容記述 | We showed that the exoplanet HAT-P-7b has an extremely tilted orbit, with a true angle of at least 86 degrees with respect to its parent star's equatorial plane, and a strong possibility of retrograde motion. We also report evidence for an additional planet or companion star. The Rossiter-McLaughlin effect was found to be a blueshift during the first half of the transit and a redshift during the second half, an inversion of the usual pattern, implying that the angle between the sky-projected orbital and stellar angular momentum vectors is 182.5 plus or minus 9.4 degrees. The third body is implicated by excess RV variation of the host star over 2 yr. Some possible explanations for the tilted orbit of HAT-P-7b are a close encounter with another planet, the Kozai effect, and resonant capture by an inward-migrating outer planet. |
| NASA分類 | Astrophysics |
| 権利 | Copyright |
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