Planets around the K-giants BD+20 274 and HD 219415
Abstract
We present the discovery of planet-mass companions to two giant stars by the ongoing Penn State-Toruń Planet Search conducted with the 9.2 m Hobby-Eberly Telescope. The less massive of these stars, K5-giant BD+20 274, has a 4.2 MJ minimum mass planet orbiting the star at a 578 day period and a more distant, likely stellar-mass companion. The best currently available model of the planet orbiting the K0-giant HD 219415 points to a >~ Jupiter-mass companion in a 5.7 year, eccentric orbit around the star, making it the longest period planet yet detected by our survey. This planet has an amplitude of ~18 m s-1, comparable to the median radial velocity "jitter," typical of giant stars.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- September 2012
- DOI:
- 10.1088/0004-637X/756/1/53
- arXiv:
- arXiv:1207.0488
- Bibcode:
- 2012ApJ...756...53G
- Keywords:
-
- planetary systems;
- stars: individual: BD+20 274 HD 219415;
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- 5 figures, 13 pages, accepted by the Astrophysical Journal. arXiv admin note: substantial text overlap with arXiv:1110.1641