IN: Conference on Faint Blue Stars, 2nd, Tucson, AZ, June 1-5, 1987, Proceedings (A89-17526 05-90). Schenectady, NY, L. Davis Press, Inc., 1987, p. 583-586. Research supported by the Consejo Superior de Investigaciones Cientificas and Rijksuniversiteit te Utrecht.
Manteiga, M.; Martinez Roger, C.; Beckman, J. E.; Pickles, A. J.
A search for binaries among 17 blue stragglers in five galactic clusters, NGC 7789, 6633, 6819, 6939, and M 67, has been performed using measurements of radial velocity variations. The spectra were obtained with the Intermediate Dispersion Spectrograph attached to the f/15 Cassegrain focus of the 2.5 m Isaac Newton Telescope at the Spanish Observatory of the Roque de los Muchachos. The wavelength coverage was 200 A, centered at 8510 A with a scale of 12.4 km/sec per pixel. All radial velocity determinations were made using cross-correlation techniques. A velocity resolution of about 3 km/sec/pixel was obtained for the standard radial velocity stars and the brighter program stars. For three of the blue stragglers variations in radial velocity greater than 30 km/sec are reported.