Confirmation of the Planet Hypothesis for the Long-period Radial Velocity Variations of Beta Geminorum

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

doi:10.1051/0004-6361:20065445

arXiv · astro-ph/0606517

Confirmation of the Planet Hypothesis for the Long-period Radial Velocity Variations of Beta Geminorum

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

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Abstract

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.

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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. 2006-06-21. Confirmation of the Planet Hypothesis for the Long-period Radial Velocity Variations of Beta Geminorum. https://doi.org/10.1051/0004-6361%3A20065445

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