标题： 食双星中的Pre-He白矮星。 III. WASP 1625-04 显示英文标题

标题： The Pre-He White Dwarfs in Eclipsing Binaries. III. WASP 1625-04

摘要： 1SWASP J162545.15-043027.9 (WASP 1625-04) 被宣布为表现出全部主食凌日和椭圆变率的EL CVn候选体之一。 本文基于我们从2015年至2020年进行的高分辨率光谱分析，给出了这个双星系统的绝对属性。 通过光谱分析，得到了两个成分的径向速度（RV），有效温度为$T_{\rm eff,1} = 8990 \pm 200$ K，质量较大的主星自转速率为$v_1\sin$$i=53\pm5$ km s$^{-1}$。 这些RV测量值与存档的WASP测光数据一起进行了分析。 从建模中我们得到：$M_1 = 1.745 \pm 0.013$M$_\odot$，$M_2 = 0.187 \pm 0.002$M$_\odot$，$R_1 = 1.626 \pm 0.008$M$_\odot$，$R_2 = 0.290 \pm 0.003$M$_\odot$，$L_1 = 15.5 \pm 1.4$L$_\odot$，以及$L_2 = 1.84 \pm 0.16$L$_\odot$。 在赫罗图上，WASP 1625-04 A位于零龄主序上，其伴星与 0.19 M$_\odot$太阳质量的氦核白矮星模型在恒定光度阶段很好地吻合。 我们的改进结果表明，WASP 1625-04 是一个典型的薄盘群体中的 EL CVn 型双星系统，具有低质量比和$M_2$组合，并且是前身双星系统的稳定、非保守质量转移的产物。 显示英文摘要

摘要： 1SWASP J162545.15-043027.9 (WASP 1625-04) has been announced as one of EL CVn candidates showing total primary eclipses and ellipsoidal variations. This paper presents the absolute properties of the binary star, based on our high-resolution spectroscopy conducted from 2015 through 2020. From the spectral analysis, the radial velocities (RVs) for both components were obtained with the effective temperature $T_{\rm eff,1} = 8990 \pm 200$ K and the rotational rate $v_1\sin$$i=53\pm5$ km s$^{-1}$ for the more massive primary. The RV measurements were analyzed with archival WASP photometry. From the modelling we obtained: $M_1 = 1.745 \pm 0.013$ M$_\odot$, $M_2 = 0.187 \pm 0.002$ M$_\odot$, $R_1 = 1.626 \pm 0.008$ M$_\odot$, $R_2 = 0.290 \pm 0.003$ M$_\odot$, $L_1 = 15.5 \pm 1.4$ L$_\odot$, and $L_2 = 1.84 \pm 0.16$ L$_\odot$. In the Hertzsprung-Russell diagram, WASP 1625-04 A lies on the zero-age main sequence and its companion accords well with the helium-core white dwarf models of 0.19 M$_\odot$ in the constant luminosity phase. Our improved results demonstrate that WASP 1625-04 is a typical EL CVn-type binary with a low mass ratio and $M_2$ combination in the thin-disk population and is the product of the stable, non-conservative mass transfer of the precursor binary.