Journal
ASTROPHYSICAL JOURNAL LETTERS
Volume 703, Issue 2, Pages L99-L103Publisher
IOP PUBLISHING LTD
DOI: 10.1088/0004-637X/703/2/L99
Keywords
planetary systems; planetary systems: formation; stars: individual (HAT-P-7); stars: rotation
Categories
Funding
- NSF [AST-0702821]
- Netherlands Organisation for Scientific Research (NWO)
- NASA [NNX09AD36G, NNX09AB33G]
- MIT
- NASA [120925, NNX09AD36G, 120361, NNX09AB33G] Funding Source: Federal RePORTER
Ask authors/readers for more resources
We show 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 evidence for the unparalleled orbit and the third body is based on precise observations of the star's apparent radial velocity (RV). The anomalous RV due to rotation ( 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 degrees.5 +/- 9 degrees.4. 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.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available