Radial velocity measurements in the Pleiades

High-resolution radial velocities for 71 stars of both early and late spectral types in the Pleiades cluster have been obtained in order to investigate the possibility of establishing an early-type star velocity system by bootstrapping late-type velocity standards to early-type ones in young clusters. It is shown that in the absence of early-type velocity standards the velocity scale of the early-type spectra in the cluster can be tied into the IAU velocity system by examining the velocity distributions of both the early-type and the late-type stars, since the internal velocity dispersion in an open cluster is less than about 1 km/s. It is found that the cluster velocity of the Pleiades is 6.0 km/s, with an observed velocity dispersion of 1 km/s. Based on these velocity results, a list of potentially constant velocity B and A stars is proposed for further studies to confirm the constancy of their velocities.