Galactic Rotation Determined from Radial Velocities and Photometric Distances of Galactic Clusters.

A total of 36 galactic clusters whose photometrically determined distances are greater than 700 parse s, has radial velocities available. From an analysis of the radial velocities and distances of these cluster 1- together with the 21-cm radio data, a value of Oort's constant, A, of 15 km/sec/kpc is obtained. A con is parison of the radio data with the optical data indicates that the distance to the galactic center, R0, smaller than 10 kpc