A photometric survey for variable stars in the globular cluster M5

We present the results of a photometric survey for variable stars in the ne arby globular cluster M5. A 14.8 x 22.8 arcmin field centered on the cluste r was monitored for a total of 37 hours with a CCD camera mounted on the 1. 0-m Swope telescope. Five new variables were identified: four blue straggle rs which are SX Phe pulsating variables, and an eclipsing binary with an or bital period of 0.466 d. The eclipsing binary lies near the main-sequence t urnoff on the cluster color-magnitude diagram. We do not confirm the variab ility of any of the 10 eclipsing binaries identified in the cluster field b y Reid (1996) and Yan & Reid (1996). The dwarf nova M5-V 101 exhibited two outbursts with full amplitudes of about 2.7 mag during our observations. A V/B - V color-magnitude diagram of the surveyed field was obtained, and a p ossible extreme HB star located 2 mag below cutoff of the blue HB was ident ified.