Physical properties and evolutionary status of the W-subtype contact binary V502 Oph with a stellar companion
Physical properties and evolutionary status of the W-subtype contact binary V502 Oph with a stellar companion
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DOI：
10.1093/pasj/psw094
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发表时间：
2016-12
影响因子：
2.3
通讯作者：
Xiao Zhou;Shengbang Qian;Bin Huang;Haobo Li;Jia Zhang
中科院分区：
文献类型：
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作者：
Xiao Zhou;Shengbang Qian;Bin Huang;Haobo Li;Jia Zhang
用Wilson-Devinney(W-D)程序分析了接触双星V502 Oph的多色($B$$V$$R_c$$I_c)CCD测光曲线。结果表明，V5 0 2 Oph是一个W亚型接触($f=35.3，$)二元系。它的两个组成部分之间的温差为24万美元，质量越大的恒星表面温度越低。为了解决光照曲线的不对称性(O‘Connell效应)，我们在模型中加入了一个冷光点，并在光照曲线的建模中首次检测到了第三光。结合轨道倾角(I=76.4)和公布的V502Oph质量函数，确定了两组分的绝对物理参数：M_1=0.46(PM0.02)M_(ODOT)，M_2=1.37(PM0.02)M_(ODOT)，R_1=0.94(PM0.01)R_(ODOT)，R_2=1.51(PM0.01)R_(ODOT)，L_1=1.13(\pm0.02)L_\oot$和$L_2=2.49(\pm0.03)L_\oot$。讨论了V502 Oph的形成和演化状态。收集了V502Oph附近所有的光电和CCD光最小时刻，并分析了它的轨道周期变化。结果表明，V502Oph的轨道周期以dp/dt=-1.69倍/年的速率持续减小，相当于$\frac{dM_{2}}{dt}=-3.01\times{10^{-8}}M_\odot/year$.的守恒传质速率光程时间效应(LTTE)是由于存在一个周期为$P_3=18.7$年、振幅为0.00402天的近距离第三分量所致。V502 Oph是综合研究光曲线、O-C曲线和光谱观测的双星和多星系统形成和演化理论的理想靶标。
Multi-color ($B$ $V$ $R_c$ $I_c$) CCD photometric light curves of the contact binary V502 Oph are analyzed using the Wilson-Devinney (W-D) program. The solutions reveal that V502 Oph is a W-subtype contact ($f = 35.3\,\%$) binary system. The temperature difference between its two components is $240K$ and the more massive star has a lower surface temperature. A cool spot is added in our model to account for the light curves' asymmetry (O'Connell effect) and third light is detected for the first time in the light curves' modeling. Combining the orbital inclination ($i = 76.4^{\circ}$) with the published mass function of V502 Oph, the absolute physical parameters of the two components are determined, which are $M_1= 0.46(\pm0.02)M_\odot, M_2=1.37(\pm0.02)M_\odot, R_1=0.94(\pm0.01)R_\odot, R_2=1.51(\pm0.01)R_\odot, L_1=1.13(\pm0.02)L_\odot$ and $L_2=2.49(\pm0.03)L_\odot$. The formation and evolutionary status of V502 Oph are discussed. All photoelectric and CCD times of light minimum about V502 Oph are gathered and its orbital period variations are analyzed. The results show that the orbital period of V502 Oph is decreasing continuously at a rate of $dP/dt=-1.69\times{10^{-7}}day\cdot year^{-1}$, which corresponds to a conservative mass transfer rate of $\frac{dM_{2}}{dt}=-3.01\times{10^{-8}}M_\odot/year$. The light-travel time effect (LTTE) is due to the presence of a close-in tertiary component with a period of $P_3=18.7$ years and an amplitute of 0.00402days. V502 Oph is an ideal target to test the formation and evolution theories of binary and multiple systems in which the light curves, $O - C$ curve and spectroscopic observations are comprehensively researched.