Radial Velocities of Giant Stars in Globular Clusters

We report radial velocities for 303 giant stars in the globular clusters M3, M13, M15, and M92. Spectra were obtained using the 4 m Mayall and 3.5 m WIYN telescopes and the Hydra fiber positioner between 1993 and 1997; most spectra were provided by the NOAO WIYN Queue Program. Observations spanned times from a few days to several months. The uncertainties in the velocity measurements are typically 1 km s(-1) or less. Several stars show velocity variations which may result from binary companions or atmospheric motions. Mean cluster velocities were measured to be -147.0 +/- 0.3, -245.5 +/- 1.0, -106.2 +/- 0.3, and -120.3 +/- 0.3 km s(-1), for M3, M13, M15, and M92, respectively. Radial velocity observations for the photometric variable V73 (vZ 1406) in M3 confirm that the star varies with a period of 0.67 days.