Eclipsing binaries from the cstar project at dome a, Antarctica

• Main Authors: Zhang, Hui, Wang, Songhu, Zhou, Ji-Lin, Zhou, Xu, Wang, Lingzhi, Wang, Lifan, Wittenmyer, R. A., Liu, Hui-Gen, Meng, Zeyang, Ashley, M. C. B., Storey, J. W. V., Bayliss, D., Tinney, Chris, Wang, Ying, Wu, Donghong, Liang, Ensi, Yu, Zhouyi, Fan, Zhou, Feng, Long-Long, Gong, Xuefei, Lawrence, J. S., Liu, Qiang, Luong-Van, D. M., Ma, Jun, Wu, Zhenyu, Yan, Jun, Yang, Huigen, Yang, Ji, Yuan, Xiangyan, Zhang, Tianmeng, Zhu, Zhenxi, Zou, Hu
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: American Astronomical Society 2015
• Subjects: binaries: eclipsing; catalogs; methods: data analysis; site testing; stars: statistics; techniques: photometric; South Pole; Antarc*; Antarctica; South pole
• Online Access: http://hdl.handle.net/1885/15401

The Chinese Small Telescope ARray (CSTAR) has observed an area around the Celestial South Pole at Dome A since 2008. About 20,000 light curves in the i band were obtained during the observation season lasting from 2008 March to July. The photometric precision achieves about 4 mmag at i = 7.5 and 20 mmag at i = 12 within a 30 s exposure time. These light curves are analyzed using Lomb–Scargle, Phase Dispersion Minimization, and Box Least Squares methods to search for periodic signals. False positives may appear as a variable signature caused by contaminating stars and the observation mode of CSTAR. Therefore, the period and position of each variable candidate are checked to eliminate false positives. Eclipsing binaries are removed by visual inspection, frequency spectrum analysis, and a locally linear embedding technique. We identify 53 eclipsing binaries in the field of view of CSTAR, containing 24 detached binaries, 8 semi-detached binaries, 18 contact binaries, and 3 ellipsoidal variables. To derive the parameters of these binaries, we use the Eclipsing Binaries via Artificial Intelligence method. The primary and secondary eclipse timing variations (ETVs) for semi-detached and contact systems are analyzed. Correlated primary and secondary ETVs confirmed by false alarm tests may indicate an unseen perturbing companion. Through ETV analysis, we identify two triple systems (CSTAR J084612.64-883342.9 and CSTAR J220502.55-895206.7). The orbital parameters of the third body in CSTAR J220502.55-895206.7 are derived using a simple dynamical model. This research has been supported by the Key Development Program of Basic Research of China (No. 2013CB834900), the National Natural Science Foundations of China (Nos. 10925313, 11003010, and 11333002), Strategic Priority Research Program “The Emergence of Cosmological Structures” of the Chinese Academy of Sciences (grant No. XDB09000000), the Natural Science Foundation for the Youth of Jiangsu Province (No. BK20130547), Jiangsu Province Innovation for PhD candidate (No. KYZZ_0030 and KYLX_0031), 985 Project of Ministration of Education and Superiority Discipline Construction Project of Jiangsu Province.