Radial Velocities of F and G Dwarfs in the Orion Cluster Region

Abstract

The interest in the distribution of rotational velocities of red dwarfs in open clusters has been recently enhanced by the discovery of W dwarfs in the Pleiades showing light variability of short period (van Leeuwen and Alphenaar, 1982) and correspondingly large Vsini values (Stauffer et al., 1984b). Below a given mass limit, slow and rapid rotators coexist at the same B-V index. Therefore, the distribution of Vsini presents two components: one very peaked at low values and a second one, rather broad. The reality of this unique feature has been beautifully confirmed by the observations of faint stars in the α Persei cluster (Stauffer et al., 1984a).