Confirmation of the Planet Hypothesis for the Long-period Radial   Velocity Variations of Beta Geminorum
  We present precise stellar radial velocity measurements for the K giant star Beta Gem spanning over 25 years. These data show that the long period low amplitude radial velocity variations found by Hatzes & Cochran (1993) are long-lived and coherent. An examination of the Ca II K emission, spectral line shapes from high resolution data (R = 210,000), and Hipparcos photometry show no significant variations of these quantities with the RV period. These data confirm the planetary companion hypothesis suggested by Hatzes & Cochran (1993). An orbital solution assuming a stellar mass of 1.7 M_sun yields a period, P = 589.6 days, a minimum mass of 2.3 M_Jupiter, and a semi-major axis, and a = 1.6 AU. The orbit is nearly circular (e = 0.02). Beta Gem is the seventh intermediate mass star shown to host a sub-stellar companion and suggests that planet-formation around stars much more massive than the sun may common. 
A.P. Hatzes, W.D. Cochran, M. Endl E.W. Guenther, S.H. Saar, G.A.H.   Walker, S. Yang, M. Hartmann, M. Esposito, D.B. Paulson