A Detached Eclipsing Binary with a Period Shorter than 0.2 Days in a Triple System
A Detached Eclipsing Binary with a Period Shorter than 0.2 Days in a Triple System
复制标题
三重系统中周期小于 0.2 天的分离食双星
DOI：
10.1088/1538-3873/aafeab
复制
发表时间：
2019
影响因子：
3.5
通讯作者：
Wang Q-S
中科院分区：
文献类型：
--
作者：
Zhang Bin;Qian S-B;Zhi Q-J;Liu N-P;Dong A-J;Michel R.;Zhu L-Y;Li K.;Zhang J.;Wang Q-S
W UMa型双星有一个明显的短周期截止，大约为0.2天。轨道周期短于这个极限的密近双星对于理解这类双星的形成和演化是非常有用的。2 MASS J11553339+3544399（以下简称J1155）是一颗红矮星双星，周期为0.199724天。利用Wilson-Devinney（W-D）程序计算和分析了超短周期食双星J1155的多色（V，R，Rc，I，Ic，W）光变曲线。我们发现，J1155属于一个罕见的组脱离红矮星EB的周期低于接触双星的周期限制（其他两个是BW 03 V38和GSC 2314-0530）。它具有0.90的高质量比。主要成分（质量更大、温度更高的星星）占据了临界洛希瓣的90%，而次要成分占据了约84.8%。这两个分量的质量和半径分别估计为M1 = 0.475 ± 0.035 M <$，M2 = 0.441 ± 0.044 M <$，R1 = 0.516 ± 0.089 R <$，R2 = 0.491 ± 0.105 R <$。通过分析所有可用的光极小时间，首次研究了该双星系统的轨道周期变化。我们发现，（O-C）（计算的）图显示了一个周期振荡，振幅为0.00326天，周期约为9.84年。这种振荡被解释为光传播时间效应（LTTE）通过第三体的存在。三重系统中第三分量的质量计算为M3 sin（i′）<$0.127 M <$。中心双星和第三颗双星的轨道距离约为4.0 Au。第三体和磁制动可能通过从中心系统中提取角动量而在J1155的形成和演化中起重要作用。
W UMa-type binary stars have an apparent short-period cutoff around 0.2 days. Close binaries with orbital periods shorter than this limit are very useful for understanding the formation and evolution of this type of binaries. 2MASS J11553339+3544399 (hereafter J1155) is a red-dwarf binary with a period of 0.199724 days. Multicolor (V, R, Rc, I, Ic, W) light curves (LCs) for the ultrashort-period eclipsing binary (EB) J1155 are presented and analyzed by using the Wilson-Devinney (W-D) code. We find that J1155 belongs to a rare group of detached red-dwarf EB with periods below the period limit of contact binaries (the other two are BW03 V38 and GSC 2314-0530). It has a high-mass ratio of 0.90. The primary component (the more massive and hotter star) is filling 90% of the critical Roche lobe, while the secondary one is filling about 84.8%. The masses and radii of the two components are estimated as M1 = 0.475 ± 0.035 M⊙, M2 = 0.441 ± 0.044 M⊙, R1 = 0.516 ± 0.089 R⊙, and R2 = 0.491 ± 0.105 R⊙, respectively. By analyzing all available times of light minimum, the orbital period changes of the binary system are investigated for the first time. We find that the (O − C) (observed-calculated) diagram shows a cyclic oscillation with an amplitude of 0.00326 days and a period about 9.84 years. This oscillation is explained as the light-travel time effect (LTTE) via the presence of a third body. The mass of the third component in the triple system is computed to be M3 sin (i′) ∼ 0.127 M⊙. The orbital distance between the central binary and the tertiary component is about 4.0 au. It is possible that the third body and the magnetic braking may play important roles in the formation and evolution of J1155 by drawing angular momentum from the central system.