SPECTROSCOPY AND ORBIT DETERMINATION OF THE CHROMOSPHERICALLY ACTIVE DOUBLE-LINED BINARY-SYSTEM HD-163621=V835 HERCULIS

HD 163621 is a double-lined spectroscopic binary in a circular orbit w hose period is 3.3 days. Spectral classification of the components has proved difficult, but current results of K0 V and late K V are reason ably consistent with our best model of the system, which has spectral types of G8 V and K7 V. The object shows photometric variability and c hromospheric activity and is therefore a member of the BY Draconis cla ss of variables. The minimum masses are quite small, 0.10 and 0.07 M. for the primary and secondary, respectively, suggesting an orbital inc lination of about 30-degrees. The system is synchronously rotating. It s distance is estimated to be 31 pc, which makes it an excellent candi date for a trigonometric parallax determination.