论文标题
长周期黯然失色的二进制：朝着真正的质量露光关系。 ii。 NN DEL系统的绝对参数
Long-period eclipsing binaries: towards the true mass-luminosity relation. II. Absolute parameters of the NN Del system
论文作者
论文摘要
我们介绍了我们对长期黯然失色的二进制恒星NN Delphini（以下简称NN DEL）的研究结果。结果基于通过南部非洲大型望远镜（SALT）的HRS Echelle光谱仪获得的光谱数据。我们的构建速度曲线基于2017年至2019年之间获得的19个光谱，涵盖了二进制轨道的所有阶段。轨道周期为p = 99.252天，是根据我们的光谱数据确定的，并与先前研究中确定的时期以及$ e = 0.517 $的系统偏心率一致。计算出的两个组件的速度振幅使我们能够确定两个系统组件M_1 = 1.320 m_sun和M_2 = 1.433 M_SUN的质量，其准确性分别约为1％（0.8％和1.1％）。 Luminosities of both components are presented as L_1 = 4.164 L_sun and L_2 = 6.221 L_sun, and the effective temperatures of both components were directly evaluated (T_eff = 6545~K and T_eff = 6190~K) together with the metallicity of the system [Fe/H] = -0.19 dex and its color excess E(B-V)=0.026~mag.与进化轨道的比较表明，系统年龄为2.25 +/- 0.19 GYR，并且两个组件都在主序列上，尚未通过转弯点。光谱类型为F5V，对于更热的组件，另一个是F8V。
We present results of our study of the long-period eclipsing binary star NN Delphini (hereafter NN Del). The results are based on spectral data obtained with the HRS echelle spectrograph of the Southern African Large Telescope (SALT). Our constructed velocity curve is based on 19 spectra obtained between 2017 and 2019 years and covers all phases of the binary's orbit. The orbital period, P=99.252 days, was determined from our spectral data and coincides with the period determined in previous studies, as well as the system eccentricity of $e=0.517$. Calculated velocity amplitudes of both components allow us to determine the masses of both system components M_1 = 1.320 M_sun and M_2 = 1.433 M_sun with the accuracy about of one percent (0.8% and 1.1%), respectively. Luminosities of both components are presented as L_1 = 4.164 L_sun and L_2 = 6.221 L_sun, and the effective temperatures of both components were directly evaluated (T_eff = 6545~K and T_eff = 6190~K) together with the metallicity of the system [Fe/H] = -0.19 dex and its color excess E(B-V)=0.026~mag. Comparison with evolutionary tracks shows that the system age is 2.25+/-0.19 Gyr, and both components are on the main sequence and have not yet passed the turn point. Spectral type is F5V for the hotter component and F8V for another one.
