摘要
本文就作者在1987和1986年分别取得的AA UMa测光和视向速度资料,利用Wilson-Devinney程序作联合求解,得到AA UMa的光变曲线和视向速度之联合解参数。其中加权质比q=1.8157±0.0099;绝对参量分别为:M_1=0.85M_⊙,M_2=1.55M_⊙,A=3.39R_⊙,R_1=1.14R_⊙和R_2=1.50R_⊙;过相接度f=0.15±0.01。根据作者获得的六个极小时刻及文献中前人的结果,本文给出了AA UMa的新的历元公式: Min.I(J.D.Hel.)=2,446,885.1119+0~d.46812583E.
New B, V light curves and precise radial velocity curves of the W-type W UMa system AA UMa have been solved simultaneously using the Wilson-Devinney Synthetic code and the solution elements have been recovered despite the presence of a large O'Connell effect in the light curves. The unrectified light curves are modeled by placing a large cool spot on the cooler star (component 2), to represent the asymmetric light variation with phase. Although most of the modelings were carried out in a contact system mode, trials were also carried out for semidetached and detached models, the results of which confirmed the contact nature of the system. The system is a W-type W UMa system in which the smaller and less massive component is the hotter one. The absolute parameters are derived and listed in Table 5. The radii are the mean volume radii and are given in solar units, similiarly, the masses and the separation of centers, also in solar masses and solar radii. The weighted mass ratio of the system is about 1.8157 + 0.0099. We find the masses to be 0.85 and 1.55, the separation of centers is 3.39. The radii are 1.14 and 1.50 for the components 1 and 2 respectively. The components are shown to be in shallow contact with a contact parameter of 0.15±0.01.All times of minima of AA UMa available in the literature have been collected, and they are listed in Table 3. A new ephemeris is derived from a least-squares fit to the data, the (O-C) residuals were calculated by the following:Min. I(J. D. Hel.) =2,446,885.1119(21)+ 0.d46812583(21)E.
