KINEMATICS AND AGE OF RS CANUM-VENATICORUM AND BY DRACONIS STARS

Space velocities of 146 chromospherically active binary stars have been calculated. Containing F-M spectral types on the main sequence together with G and K giants and subgiants, this very heterogeneous sample has been divided into groups in order to segregate stars which have similar kinematics and ages. After many trials for different criteria, the sample was divided into five groups: two groups for giants, two groups for main-sequence systems, and one group for main-sequence systems. Kinematics of subgiants implies a stellar age of approximately 2-3 Gyr. Young and old groups of giants and main-sequence systems could be characterized by a kinematical age of approximately 1 Gyr and > 5 Gyr, respectively. These ages are estimated approximately according to space velocity distributions and dispersions in velocity space in each group. Inferred ages for the groups above agrees with circularization, rotation activity relation, and stellar evolution theories.