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 (PTPS) 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 \sim18 m/s, comparable to the median radial velocity (RV) "jitter", typical of giant stars.

5 figures, 13 pages, accepted by the Astrophysical Journal. arXiv admin note: substantial text overlap with arXiv:1110.1641