Abstract
We report on observations of the Rossiter-McLaughlin (RM) effect for the XO-3 exoplanetary system. The RM effect for the system was previously measured by two different groups, but their results were statistically inconsistent. To obtain a decisive result, we observed two full transits of XO-3b with the Subaru 8.2-m telescope. By modeling these data with a new and more accurate analytic formula for the RM effect, we found the projected spin-orbit angle to be λ = 37.°3±3.°0, in good agreement with a previous finding by Winn et al. (2009 ApJ, 700, 302). In addition, an offset of ∼l22ms -1 was observed between the two transit datasets. This offset could be a signal of a third body in the XO-3 system, a possibility that should be checked with future observations. We also attempted to search for a possible signature of the stellar differential rotation in the RM data for the first time, and put weak upper limits on the differential rotation parameters.
Original language | English (US) |
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Pages (from-to) | L57-L61 |
Journal | Publications of the Astronomical Society of Japan |
Volume | 63 |
Issue number | 6 |
DOIs | |
State | Published - Dec 25 2011 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science
Keywords
- Stars: planetary systems: pindividual (XO-3)
- Stars: rotation
- Techniques: radial velocities
- Techniques: spectroscopic