Photometric solution and period analysis of the contact binary system AH Cnc  

作　　者：Ying-Jiang Peng Zhi-Quan Luo Xiao-Bin Zhang Li-Cai Deng Kun Wang Jian-Feng Tian Zheng-Zhou Yan Yang Pan Wei-Jing Fang Zhong-Wen Feng De-Lin Tang Qi-Li Liu Jin-Jiang Sun Qiang Zhou 

机构地区：[1]Physics and Space Science College, China West Normal University, Nanchong, 637002, China [2]National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China [3]Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008, China [4]School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054, China

出　　处：《Research in Astronomy and Astrophysics》2016年第10期63-70,共8页天文和天体物理学研究（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos. U1131121,11303021,U1231202,11473037 and 11373073)

摘　　要：Photometric observations of AH Cnc, a W UMa-type system in the open cluster M67, were car- fled out by using the 50BIN telescope. About 100h of time-series/3- and V-band data were taken, based on which eight new times of light minima were determined. By applying the Wilson-Devinney method, the light curves were modeled and a revised photometric solution of the binary system was derived. We con- firmed that AH Cnc is a deep contact （f = 51%）, low mass-ratio （q - 0.156） system. Adopting the distance modulus derived from study of the host cluster, we have re-calculated the physical parameters of the binary system, namely the masses and radii. The masses and radii of the two components were estimated to be respectively 1.188（4-0.061） Me, 1.332（4-0.063） RQ for the primary component and 0.185（4-0.032） Me, 0.592（4-0.051） Re for the secondary. By adding the newly derived minimum timings to all the available data, the period variations of AH Cnc were studied. This shows that the orbital period of the binary is con- tinuously increasing at a rate of dp/dt = 4.29 x 10-10 d yr-1. In addition to the long-term period increase, a cyclic variation with a period of 35.26 yr was determined, which could be attributed to an unresolved tertiary component of the system.Photometric observations of AH Cnc, a W UMa-type system in the open cluster M67, were car- fled out by using the 50BIN telescope. About 100h of time-series/3- and V-band data were taken, based on which eight new times of light minima were determined. By applying the Wilson-Devinney method, the light curves were modeled and a revised photometric solution of the binary system was derived. We con- firmed that AH Cnc is a deep contact （f = 51%）, low mass-ratio （q - 0.156） system. Adopting the distance modulus derived from study of the host cluster, we have re-calculated the physical parameters of the binary system, namely the masses and radii. The masses and radii of the two components were estimated to be respectively 1.188（4-0.061） Me, 1.332（4-0.063） RQ for the primary component and 0.185（4-0.032） Me, 0.592（4-0.051） Re for the secondary. By adding the newly derived minimum timings to all the available data, the period variations of AH Cnc were studied. This shows that the orbital period of the binary is con- tinuously increasing at a rate of dp/dt = 4.29 x 10-10 d yr-1. In addition to the long-term period increase, a cyclic variation with a period of 35.26 yr was determined, which could be attributed to an unresolved tertiary component of the system.

关 键 词：methods： data analysis -- astronomical instrumentation -- binaries： eclipsing stars closestars -- Galaxy： open clusters and associations： individual （M67） 

分 类 号：P111[天文地球—天文学] P154.1