Nature of the oscillating semi-detached eclipsing binary system IO Ursae Majoris
Nature of the oscillating semi-detached eclipsing binary system IO Ursae Majoris
复制标题
振荡半分离食双星系统 IO 大熊座的性质
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
A. Liakos
中科院分区：
文献类型：
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作者：
F. Soydugan;E. Soydugan;Ç. Kanvermez;A. Liakos
本文介绍了对被忽视的半独立食双星系统 IO 大熊座 (IO UMa) 的光谱和多色光度观测分析结果。首次通过对超视距光变曲线和组件径向速度的同步分析，确定了系统的轨道参数及其组件的基本物理特性。主部件和副部件的质量和半径分别为 M1 = 2.11 ± 0.07 M�、M2 = 0.29 ± 0.02、R1 = 3.00 ± 0.04 R� 和 R2 = 3.92 ± 0.05 R�。导出的绝对参数得出 IO UMa 的光度距离为 263 ± 13 pc。测得质量增加的较热成分的预计旋转速度为 34.5 ± 2k m s -1 ，仅比同步值快 1.28 倍。系统中较热的部分位于不稳定带区域，表现为周期短、幅度小的脉动变化。从光度数据中减去理论光变曲线后的频率分析表明，质量较大的成分显示出 δ Scuti 型脉动，具有四个检测到的频率。发现 V 滤波器中变化的总幅度为 0.03 mag 。使用不同滤波器中的振幅比和相位差进行模式识别表明，22.0148 d -1 的主脉动频率可能是径向模式。
This paper presents results from analysing spectroscopic and multicolour photometric obser- vations of the neglected semi-detached eclipsing binary system IO Ursae Majoris (IO UMa). For the first time, the orbital parameters of the system and fundamental physical properties of its components were determined from simultaneous analysis of BVR light curves and radial velocities of the components. The masses and radii of the primary and secondary components were found to be M1 = 2.11 ± 0.07 M� , M2 = 0.29 ± 0.02 Mand R1 = 3.00 ± 0.04 R� and R2 = 3.92 ± 0.05 R� , respectively. Derived absolute parameters yield the photometric distance of IO UMa as 263 ± 13 pc. The projected rotational velocity of the mass-accreting hotter component was measured as 34.5 ± 2k m s −1 , just 1.28 times faster than the synchronous value. The hotter component of the system, located in the region of the instability strip, in- dicates pulsational variation with short period and small amplitude. Frequency analysis after subtracting the theoretical light curve from photometric data revealed that the more massive component shows δ Scuti type pulsation with four detected frequencies. The total amplitude of the variation in the V filter was found to be 0.03 mag . Mode identification using amplitude ratios and phase differences in different filters suggests that the main pulsation frequency of 22.0148 d −1 is probably a radial mode.