BVI photometric variability survey of M3

We have conducted a three-band (BVI) variability survey of the globular cluster M3. This is the first three-band survey of the cluster using modem image subtraction techniques. Observations were made over nine nights in 1998 on the 1.2 m telescope at the F. L. Whipple Observatory in Arizona. We present photometry for 180 variable stars in the M3 field, 12 of which are newly discovered. New discoveries include six SX Phoenicis-type variables that all lie in the blue straggler region of the color-magnitude diagram, two new first-overtone RR Lyrae variables, a candidate multimode RR Lyrae variable, a detached eclipsing binary, and two unclassified variables. We also provide revised periods for 52 of the 168 previously known variables that we observe.