The Pan-Pacific Planet Search. VII. The Most Eccentric Planet Orbiting a Giant Star
Abstract
Radial velocity observations from three instruments reveal the presence of a 4 MJup planet candidate orbiting the K giant HD 76920. HD 76920b has an orbital eccentricity of 0.856 ± 0.009, making it the most eccentric planet known to orbit an evolved star. There is no indication that HD 76920 has an unseen binary companion, suggesting a scattering event rather than Kozai oscillations as a probable culprit for the observed eccentricity. The candidate planet currently approaches to about four stellar radii from its host star, and is predicted to be engulfed on a ∼100 Myr timescale due to the combined effects of stellar evolution and tidal interactions.
- Publication:
-
The Astronomical Journal
- Pub Date:
- December 2017
- DOI:
- 10.3847/1538-3881/aa9894
- arXiv:
- arXiv:1711.05378
- Bibcode:
- 2017AJ....154..274W
- Keywords:
-
- planetary systems;
- stars: evolution;
- stars: individual (HD 76920);
- techniques: radial velocities;
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- Accepted for publication in AJ