Variable Star Status of Two Stars: V204 and I-I-39 in M3

Abstract

The star I-I-42 (=vZ1390), a cluster member in M3, located near the red edge of the instability strip of the horizontal branch, was discovered by Roberts and Sandage as a low amplitude variable, it was designated as V204 in the "second catalogue of variable stars in globular clusters", but its coordinates given in all versions of this catalogue are wrong since 1955. We argue that V204 is indeed a low amplitude HB variable star, located near to the red edge of the instability strip, with a period of 0.74785(d) and an amplitude of about 0.04 mag in V. We also find that the red cluster member star I-I-39 is a low amplitude variable with a period of 1.16(d) and amplitude of about 0.03 mag in V which might be pulsating at the second overtone.