PULSATIONS AND PERIOD CHANGES OF THE NON-BLAZHKO RR LYRAE VARIABLE Y OCT OBSERVED FROM DOME A, ANTARCTICA
PULSATIONS AND PERIOD CHANGES OF THE NON-BLAZHKO RR LYRAE VARIABLE Y OCT OBSERVED FROM DOME A, ANTARCTICA
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DOI：
10.1088/0004-6256/149/1/25
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发表时间：
2014-12
期刊：
影响因子：
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通讯作者：
Huang Zhihua;Fu Jianning;Zong Weikai;Wang Lingzhi;Macri Lucas M;Wang Li-fan;Ashley Michael C. B.
中科院分区：
文献类型：
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作者：
Huang Zhihua;Fu Jianning;Zong Weikai;Wang Lingzhi;Macri Lucas M;Wang Li-fan;Ashley Michael C. B.
2008年、2009年和2010年，中国小型望远镜阵列（CSTAR）在南极A穹运行期间，获得了大量的变星光度数据。本文介绍了在南极穹窿A用CSTAR观测到的六个天琴座RR变星之一的Y Oct的研究。i波段的光度数据是在2008年和2010年获得的，占空比（定义为代表科学可用数据的时间占CSTAR观测时间的比例）分别约为44%和52%。2009年，这颗恒星的g波段和r波段的光度数据被收集，占空比分别为65%和60%。对三个波段的数据进行傅里叶分析只显示基频及其谐波，这是非blazhko RR Lyrae变量的特征。基频和幅值以及总脉动幅值分别由三个波段的数据得到。基频幅值和总脉动幅值在g波段最大，在i波段最小。从三个季节的数据中得到了251次极大值，并与GEOS RR Lyrae数据库提供的38次极大值进行了分析。周期变化率为- 0.96±0.07天，这是一个惊人的负值。根据已有的文献关系，导出了以下物理参数：[Fe/H] = - 1.41±0.14,MV = 0.696±0.014,V−K ？> = 1.182±0.028 mag, log T ？> = 3.802±0.003 K, log g ？> = 2.705±0.004,log L / L⊙？> = 1.625±0.013,log M / M⊙？> =−0.240±0.019。
During the operation of the Chinese Small Telescope Array (CSTAR) in Dome A of Antarctica in the years 2008, 2009, and 2010, large amounts of photometric data have been obtained for variable stars in the CSTAR field. We present here the study of one of six RR Lyrae variables, Y Oct, observed with CSTAR in Dome A, Antarctica. Photometric data in the i band were obtained in 2008 and 2010, with a duty cycle (defined as the fraction of time representing scientifically available data to CSTAR observation time) of about 44% and 52%, respectively. In 2009, photometric data in the g and r bands were gathered for this star, with a duty cycle of 65% and 60%, respectively. Fourier analysis of the data in the three bands only shows the fundamental frequency and its harmonics, which is characteristic of the non-Blazhko RR Lyrae variables. Values of the fundamental frequency and the amplitudes, as well as the total pulsation amplitude, are obtained from the data in the three bands separately. The amplitude of the fundamental frequency and the total pulsation amplitude in the g band are the largest, and those in the i band the smallest. Two-hundred fifty-one times of maximum are obtained from the three seasons of data, which are analyzed together with 38 maximum times provided in the GEOS RR Lyrae database. A period change rate of −0.96 ± 0.07 days Myr−1 is then obtained, which is a surprisingly large negative value. Based on relations available in the literature, the following physical parameters are derived: [Fe/H] = −1.41 ± 0.14, MV = 0.696 ± 0.014 mag, V − K ?> = 1.182 ± 0.028 mag, log T eff ?> = 3.802 ± 0.003 K, log g ?> = 2.705 ± 0.004, log L / L ⊙ ?> = 1.625 ± 0.013, and log M / M ⊙ ?> = −0.240 ± 0.019.