EPIC 202060577的双星解轨和物理参数研究  

Physical Parameters of the Eclipsing Binary System EPIC 202060577

作　　者：赵世杰 付建宁[1] 王江涛 李春乾 王佳鑫 宗伟凯 ZHAO Shi-jie;FU Jian-ning;WANG Jiang-tao;LI Chun-qian;WANG Jia-xin;ZONG Wei-kai(Department of Astronomy,Beijing Normal University,Beijing 100875;National Astronomical Observatories,Chinese Academy of Sciences,Beijing 100101;University of Chinese Academy of Sciences,Beijing 100049)

机构地区：[1]北京师范大学天文系,北京100875 [2]中国科学院国家天文台,北京100101 [3]中国科学院大学,北京100049

出　　处：《天文学报》2021年第3期14-25,共12页Acta Astronomica Sinica

基　　金：国家自然科学基金项目(11833002)资助。

摘　　要：EPIC 202060577是一个包含B型子星的食双星系统.根据K2测光数据获得了45个次极小时刻,确定其轨道周期为1.019648 d并给出了历元公式.基于大天区面积多目标光纤光谱望远镜(Large Sky Area Multi-Object Fiber Spectroscopic Telescope,LAMOST^(1),又称郭守敬望远镜)的光谱数据,使用ROTFIT程序获得了目标系统的主星光谱型、有效温度、金属丰度与表面重力加速度,并计算得到了视向速度曲线.通过PHOEBE(Physics Of Eclipsing Binaries)建模程序和emcee(Affine Invariant Markov chain Monte Carlo Ensemble Sampler)拟合程序,对EPIC 202060577进行了轨道求解并分析了RossiterMcLaughlin效应对视向速度曲线的影响.最终结果表明EPIC 202060577是一个质量比q=0.11的分离结构食双星系统(q=M_(2)/M_(1),M_(1)、M_(2)分别为主星和伴星质量),主星的光谱型为B2/3,主星和伴星的质量、半径和有效温度分别为M_(1)=12.56M⊙和M_(2)=1.39M⊙,R_(1)=4.58Rsun和R_(2)=1.85Rsun,T1=18979 K和T2=8710 K,M⊙和Rsun分别为太阳质量和半径.根据所获得的物理参数,对EPIC 202060577的演化阶段进行了讨论.EPIC 202060577 is an eclipsing binary system containing a B-type primary star.From the K2 photometry,45 secondary minimal times were obtained.The orbital period is determined to be 1.019648 days and the epoch formula is derived.Based on LAMOST(Large Sky Area Multi-Object Fiber Spectroscopic Telescope)spectra,the ROTFIT program is used to obtain spectral class,effective temperature,metal abundance and surface gravity of the primary star,and calculate the radial velocities.Through the PHOEBE(Physics Of Eclipsing Binaries)modeling program and emcee(Affine Invariant Markov chain Monte Carlo Ensemble Sampler)fitting program,a solution of the orbital parameters is obtained and the influence of Rossiter-McLaughlin effect on the radial velocity curve is analyzed.The final solution shows that EPIC202060577 is a detached eclipsing binary system with mass ratio q=0.11,the spectral class of the primary star is B2/3.The mass,radius and effective temperature of the primary and secondary stars are M_(1)=12.56 M⊙and M_(2)=1.39 M⊙,R_(1)=4.58 Rsunand R_(2)=1.85 Rsun,T1=18979 K and T2=8710 K,respectively,here M⊙and Rsunare the solar mass and solar radius.According to the physical parameters,the evolutionary phase of EPIC 202060577 is discussed.

关 键 词：双星:掩食 技术:测光 技术:光谱 方法:数据分析 

分 类 号：P144[天文地球—天体物理]