Photometric Study of Contact Binary AW UMa

Abstract

BVRI observations of AW UMa were made from March to April during 13 nights in 1994 using the 35cm schmidt-Cassegrain telescope of Department of Astronomy and Space Science, Chungbuk National University. A total of 1092 observations (273 in B, 273 in V, 273 in R, 273 in I) were obtained. We constructed the light curves of BVRI with these observations. The one time of primary minimum light of JD Hel 2449456.1502 and the two times of secondary minimum lights of JD Hel 2449432.2412 and JD Hel 2449447.1567 were determined from our observations. Orbital period change of -0.d00000394 was determined from O-C diagram which was constructed with collected times of minimum lights. Mass transfer rate of -6.4 x 10^-7M_solar/year was derived using the period changing ratio. It is suggested that the inhomogeneous distribution of transferred matter around the secondary component would produce the irregular light variation of the AW UMa system.