A charge-coupled device photometric study of south hemispheric contact binary ae phoenicis

Abstract

The complete charge-coupled device light curves in B, V, R, and I bands of the short-period binary system, AE Phe, are presented. It is found that the light curves of AE Phe belong to typical EW-type light variation. Photometric solutions were derived by using the 2003 version of the Wilson-Devinney code. It showed that AE Phe is a W-subtype shallow-contact system (f = 14.6%(0.5%)) with a mass ratio of q = 2.5491(0.0092). The temperature difference between the two components is 227 K. Analysis of the O - C curve suggests that the period of AE Phe shows a long-term continuous increase at a rate of dP/dt = +6.17(0.44) × 10-8 days year-1. The long-term period increase, the marginal-contact configuration, and the astrophysical parameters of the binary system, all suggest that it is a shallow-contact binary undergoing a thermal relaxation oscillation evolving into a detached binary.