2001AJ....121.1091L

We present here a new photometric light curve analysis of the eclipsing binary AP Aur. The CCD photometry, performed at the Yunnan Observatory using the 1.06 m telescope, has given 179 individual data points in B and V bandpass filters. From these data we have obtained two minimum times. Based on these two minima, together with some other photoelectric minima collected from the literature, we have determined a new epoch and the rate of the period variation (p{dot}=1.268x10^–9 days.cycle^–1) of the system. The Wilson-Devinney model (first described in 1971) was used to derive the photometric solutions. AP Aur is a W UMa-type contact binary system. The mass ratio (q=m₂/m₁=0.246) suggests that the system has an A-type W UMa binary configuration. We find that the asymmetry of the light curve is most likely caused by mass transfer from the secondary to the primary or a circulation effect in the common envelope. The evolutionary status is considered, and we find that AP Aur has just evolved away from the main sequence. Finally the evolutionary future of the system is discussed.