XZ And a semidetached asynchronous binary system

Abstract

In this work the light curves (LCs) solutions along with the radial velocity curve of the semidetached binary systemXZ And are presented using the PHOEBE program(ver 0.31a). Absolute parameters of the stellar components were then determined, enabling us to discuss structure and evolutionary status of the system. The analysis indicates that the primary is a non-synchronous (i.e., F1 = 3.50 ± 0.01) Main Sequence (MS) star and the secondary is a bit more evolved, and fills its Roche critical surface. In addition, times of minima data (“O − C curve”) were analyzed. Apart from an almost parabolic variation in the general trend of O − C data, which was attributed to a mass transfer from the secondary with the rate ̇₂ = (9.52 ± 0.41) × 10⁻¹⁰M_⊙ yr⁻¹; two cyclic variations with mean periods of 34.8 ± 2.4 and 23.3 ± 3.0 yr, modulating the orbital period, were found, which were attributed to a third body orbiting around the system, and magnetic activity cycle effect, respectively.