A&A Supplement series, Vol. 123, June I 1997, 209-218
Received July 25; accepted September 25, 1996
R. Duemmler - I.V. Ilyin - I. Tuominen
Send offprint request: R. Duemmler; e-mail: Rudolf.Duemmler@oulu.fi
Department of Geosciences and Astronomy, University of Oulu, Linnanmaa, P.O. Box 333, FIN-90571 Oulu, Finland
26 high quality radial velocity measurements of the RS CVn star Gem taken in 1993, 1994, and 1995 are used in combination with older measurements to fit a new radial velocity curve. Essentially, the orbital parameters given by Bopp & Dempsey (1989) are confirmed. However, the orbit turns out to be circular. Gem is known as a single-lined binary, and also in the new spectra no trace of the secondary is found. However, combining the orbital with rotational parameters, constraints on the fundamental parameters can be found: the inclination, the radius and the two masses. The inclination is high; the mass of the primary seems to be normal for a K1 giant, its radius, however, seems to be too small.
keywords: stars: spectroscopic -- stars: fundamental parameters -- binaries: stars individual: Gem