Abstract

We present the results of spectral observations and consequent analysis of six long-period double-lined eclipsing binaries (DLEBs) with main-sequence (MS) components from a sample formed with the aim of testing the ‘‘mass–luminosity’’ relation (MLR) for stars in the \(M/M_{\odot}>1.5\) mass range. We analyzed all the obtained spectra using a technique that allows one to reveal the binary nature of the system and determine \(T_{\textrm{eff}}\) and \(\log g\) for each component, as well as the system metallicity [Fe/H] and line-of-sight extinction \(E(B-V)\). We computed the absolute parameters of the systems under consideration. An analysis of the obtained spectra shows that for three of the six objects (V1156 Cyg, EU Gem and V733 Per) we can clearly establish their binary nature and determine the spectral type and class for each component. Both components of the V733 Per system have already left the MS, and therefore the system must be excluded from our sample, whereas studies of V1156 Cyg and EU Gem should continue. OT And did not demonstrate a binary spectrum, however, the main component of the system is a hot A6 V star, and therefore, OT And should remain in our sample. We also revealed no binarity in the IM Del and LX Gem systems. Their brighter components turned out to be a cool giant and a supergiant, and these systems should be excluded from the sample based on the results of our analysis. We used the same technique to analyze the two spectra obtained for systems EU Gem and LX Gem using LAMOST. We have shown that the parameters determined from LAMOST spectra are in good agreement with the parameters determined for spectra obtained at the Caucasian Mountain Observatory (CMO) of SAI MSU. Our analysis allowed us to plot a first approximation of the V1156 Cyg velocity curves and show that the cool component in this system has a larger mass.

中文翻译：

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低分辨率光谱数据中长周期双线食双星系统成分的光谱类型

摘要

我们展示了对六个长周期双线食双星 (DLEB) 的光谱观测结果和随后的分析结果，这些双星具有主序 (MS) 成分，这些成分来自为测试“质量-光度”关系而形成的样本（ MLR) 适用于质量范围为\(M/M_{\odot}>1.5\) 的恒星。我们使用一种技术分析了所有获得的光谱，该技术允许人们揭示系统的二元性质并确定每个组件的\(T_{\textrm{eff}}\)和\(\log g\)以及系统金属丰度 [Fe/H] 和视线消光\(E(BV)\)。我们计算了所考虑系统的绝对参数。对获得的光谱的分析表明，对于六个物体中的三个（V1156 Cyg、EU Gem 和 V733 Per），我们可以清楚地确定它们的二元性质并确定每个成分的光谱类型和类别。V733 Per 系统的两个组件均已离开 MS，因此该系统必须从我们的样本中排除，而 V1156 Cyg 和 EU Gem 的研究应继续。OT And 没有展示出双星光谱，然而，该系统的主要成分是一颗热 A6 V 星，因此，OT And 应该保留在我们的样本中。我们还揭示了 IM Del 和 LX Gem 系统中没有二元性。它们更亮的部分被证明是一个冷巨星和一个超巨星，根据我们的分析结果，这些系统应该从样本中排除。我们使用相同的技术来分析使用 LAMOST 为 EU Gem 和 LX Gem 系统获得的两个光谱。我们已经证明，从 LAMOST 光谱确定的参数与在 SAI MSU 的高加索山天文台 (CMO) 获得的光谱确定的参数非常一致。我们的分析使我们能够绘制 V1156 Cyg 速度曲线的第一个近似值，并表明该系统中的冷组件具有更大的质量。