2012/09/06 by B.-C. Lee, Byeong-Cheol Lee, I. Han +7 · 2 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysical Phenomena and Observations #Stellar, planetary, and galactic studies #astro-ph.EP #astro-ph.SR
paper · pdf · doi:10.1051/0004-6361/201219347
5 pages, 7 figures, 3 tables, accepted for publisation in Astronomy & Astrophysics
arxiv created 2012/09/06 · openalex publication_date 2012/09/07 · arxiv updated 2015/06/11 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31
Aims. Our aim is to search for and study the origin of the low-amplitude and long-periodic radial velocity (RV) variations in K giants. Methods. We present high-resolution RV measurements of K2 giant epsilon CrB from February 2005 to January 2012 using the fiber-fed Bohyunsan Observatory Echelle Spectrograph (BOES) at the Bohyunsan Optical Astronomy Observatory (BOAO). Results. We find that the RV measurements for epsilon CrB exhibit a periodic variation of 417.9 +/- 0.5 days with a semi-amplitude of 129.4 +/- 2.0 m/s. There is no correlation between RV measurements and chromospheric activity in the Ca II H region, the Hipparcos photometry, or bisector velocity span. Conclusions. Keplerian motion is the most likely explanation, with the RV variations arising from an orbital motion. Assuming a possible stellar mass of 1.7 +/- 0.1 MSun for epsilon CrB, we obtain a minimum mass for the planetary companion of 6.7 +/- 0.3 MJup with an orbital semi-major axis of 1.3 AU and eccentricity of 0.11. We also discuss the implications of our observations for stellar metallicity versus planet occurrence rate and stellar mass versus planetary mass relations.