A Common Proper Motion Stellar Companion to HAT-P-7
Abstract
We report that HAT-P-7 has a common proper motion stellar companion. The companion is located at ∼3."9 to the east and estimated to be an M5.5V dwarf based on its colors. We also confirm the presence of a third companion, which was first reported by Winn et al. (2009, ApJ, 703, L99), based on long-term radial velocity measurements. We revisit the migration mechanism of HAT-P-7b given to the presence of those companions, and propose the sequential Kozai migration as a likely scenario in this system. This scenario may explain the reason for an outlier in the discussion of the spin-orbit alignment timescale for HAT-P-7b by Albrecht et al. (2012, ApJ, 757, 18).
- Publication:
-
Publications of the Astronomical Society of Japan
- Pub Date:
- December 2012
- DOI:
- 10.1093/pasj/64.6.L7
- arXiv:
- arXiv:1209.4422
- Bibcode:
- 2012PASJ...64L...7N
- Keywords:
-
- stars: binaries: general;
- stars: planetary systems: individual (HAT-P-7);
- techniques: high angular resolution;
- techniques: photometric;
- techniques: radial velocities;
- Astrophysics - Earth and Planetary Astrophysics;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 5 pages, 4 figures, 2 tables, PASJ Letters in press