Are All Blue Stragglers Binaries?

Radial velocity studies for five bright blue stragglers are reported and cluster membership is confirmed for four of them. Two of the stars show no significant radial velocity variations on a timescale of about 75 days and two others show no significant variation on timescales of 15 and 30 days respectively. The star for which cluster membership is uncertain may be a velocity variable. The data do not support the theory of blue straggler production involving mass transfer in a close binary. A spread in formation time of the stars in a cluster is shown to be a plausible explanation of the blue stragglers studied.This title from the Steward Observatory Preprints collection is made available by the Steward Observatory Parker Library and the University Libraries, The University of Arizona. If you have questions about titles in this collection, please contact Parker Library librarian Betty Fridena, bfridena@as.arizona.edu