R Canis Majoris is a bright, short-period (1d.1359) Algol-type eclipsing binary. For a long time, it was considered to be a low-mass binary star with M1 = 1.1M⊙ and M2 = 0.17M⊙ primary and secondary components, respectively (Tomkin, 1985). Glazunova, Yushchenko & Mkrtichian (2009) found new masses for the primary and secondary components of M1=1.81M⊙ and M2=0.23M⊙, respectively and resolved a long-standing problem with the low masses of components for this binary. Budding and Butland (2011) confirmed the results of Glazunova, Yushchenko & Mkrtichian and obtained improved orbits and masses. New spectroscopic observations of R CMa were done during 8 nights on December 2012 with the 2.4-meter telescope of the Thai National Observatory (TNO) and fibre-fed medium resolution echelle spectrograph. We obtained new, accurate orbital radial velocities of the two components of this binary system. Results of these investigations and the new orbital parameters are presented.
To detect exoplanets and study pulsation of K giant stars, we have observed precise RV (radial velocity) of about 55 early K giant (K0 - K4) stars brighter than V = 5 magnitude since 2003 by using BOES, a high resolution Echelle spectrograph attached to the 1.8 m telescope at BOAO (Bohyunsan Optical Astronomy Observatory). We detected periodic RV variation of KO III star β Gem (HD 62509) with a period P=596.6 ± 2.3 days and a semi-amplitude K=44.8 ± 0.7 ms-1 If we adopt 1.7 M⊙ for the mass of β Gem, this yields the minimum mass of the companion m sin i = 2.64 M Jupiter results agree well with Hatzes et al. (2006) and Reffert et al. (2006), and confirm their discovery of a planetary object around β Gem. We also confirmed about 192 minutes short period stellar oscillation found by Hatzes and Zechmeister (2007). This is the first report of exoplanet detection using BOES and demonstrates that the RV observation using BOES is accurate and stable enough to detect exoplanets around bright K giant stars.