Exoplanets in the Antarctic Sky. IV. Dual-band Photometry of Variables Found by the CSTAR-II Commissioning Survey at the North Sky

• Published in: The Astronomical journal 2020-04, Vol.159 (4), p.172
• Main Authors: Zhu, Jiapeng, Zhang, Hui, Liang, En-Si, Yu, Zhouyi, Yang, Ming, Zhou, Ji-lin, Cui, Xiangqun, Du, Fujia, Gong, Xuefei, Gu, Bozhong, Hu, Lei, Jiang, Peng, Liu, Huigen, Li, Xiaoyan, Li, Zhengyang, Mould, Jeremy, Sun, Tianrui, Suntzeff, Nicholas B., Tao, Charling, Tian, Qiguo, Uddin, Syed A., Wang, Lifan, Wang, Songhu, Wang, Xiaofeng, Wei, Peng, Wright, Duncan, Wittenmyer, Robert A., Xu, Lingzhe, Yang, Shihai, Yuan, Xiangyan, Zhou, Hongyan, Zhu, Zhenxi, Lu, Hongke
• Format: Article
• Language: English
• Subjects: Astronomy; ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; Chromaticity; ECLIPSE; Eclipses; Eclipsing binary stars; Extrasolar planets; Field of view; Light curve; Multi-color photometry; PHOTOMETRY; Planet detection; PLANETS; Polar environments; Pulsating variable stars; Sky surveys (astronomy); STARS; Surveys; TELESCOPES; Transit
• ISSN: 0004-6256; 1538-3881; 1538-3881
• DOI: 10.3847/1538-3881/ab7449

From the experiences learned in three decades of exoplanet search, wide-field transit surveys have proven to be one of the most effective ways to detect exoplanets. Wide field of view, however, suffers from high false-positive rates caused by blended eclipsing binaries. The chromaticity in eclipse depth is an effective feature to distinguish low-depth eclipsing binaries from transiting exoplanets, making multiple-band photometry follow-up advantageous before a target is passed onto more expensive spectroscopic follow-up. Moreover, a multiple-band photometric survey is itself a powerful method to find and vet planetary candidates and narrow down the candidate list of high-priority targets. In this work, we report the first results of a dual-band (Sloan-g and -i) wide-field photometry survey-the Chinese Small Telescope ARray II (CSTAR-II), an updated version of the original CSTAR. As a key component of the Chinese Exoplanet Searching Program from Antarctica, CSTAR-II has been tested thoroughly at a remote arctic site near Mohe during the winter of 2014. In total, 13,531 light curves with the best overall photometric precision of ∼3 mmag were extracted from 7721 stars in the Sloan-g and -i bands. Using a robust method, we have detected 63 variables, of which 48 are newly discovered. The dual-band photometric results as well as the stellar properties of the detected sources are provided in this work.