Observations of variable stars in the globular cluster M80

Abstract

Observations of the globular cluster M80 obtained between 1939 and 1987 are examined. The observations have resulted in the discovery of ten variable stars in or near the cluster. The colors and periods of these variable stars are discussed. For the nine stars with known periods, blue light curves are obtained. The light curves of the five variables farthest from the cluster center are obtained. Consideration is given to the shape of the light curve and position in the period-luminosity diagram of V1, a W Virginis star whose light curve and period have not changed over the 50 yrs of observations. Also, the nova T Sco 1860 is discussed, noting the possibility of searching for the nova using modern technology.