SIMBAD references

Our aim is to search for and study the origin of the low-amplitude and long-periodic radial velocity (RV) variations in K giants. We present high-resolution RV measurements of K2 giant ε CrB from February 2005 to January 2012 using the fiber-fed Bohyunsan Observatory Echelle Spectrograph (BOES) at the Bohyunsan Optical Astronomy Observatory (BOAO). We find that the RV measurements for ε CrB exhibit a periodic variation of 417.9±0.5-days with a semi-amplitude of 129.4±2.0m/s. There is no correlation between RV measurements and chromospheric activity in the CaII H region, the Hipparcos photometry, or bisector velocity span. Keplerian motion is the most likely explanation, with the RV variations arising from an orbital motion. Assuming a possible stellar mass of 1.7±0.1M_☉ for ε CrB, we obtain a minimum mass for the planetary companion of 6.7±0.3M_Jup with an orbital semi-major axis of 1.3AU 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.