论文标题
TYC〜2990-127-1：一个属于子巨头和红色巨人的Algol-type SB2 SB2二进制系统，有可能正在进行的质量转移
TYC~2990-127-1: an Algol-type SB2 binary system of subgiant and red giant with a probable ongoing mass-transfer
论文作者
论文摘要
我们介绍了Lamost调查中光谱二进制TYC 2990-127-1的研究。我们使用全光谱拟合来得出径向速度和光谱参数。高质量比表明该系统过去经历了传质。我们计算轨道溶液，发现它是圆形轨道上非常接近的亚巨型/红色巨型对，略微倾斜到天空平面。苔丝光学数据的拟合证实了这一点，并表明I \ sim 39.8度的倾向。 H_ALPHA周围的光曲线和光谱显示出不规则可变性的迹象，这支持持续的传质。二进制进化模拟表明，二进制可能以0.3的积聚效率经历非保守的传质，并且在随后的进化中，二进制将进入共同的包膜阶段。弹出共同包膜后的残留产物可以是独立的双氦白色矮人（He WD）或合并。
We present a study of the spectroscopic binary TYC 2990-127-1 from the LAMOST survey. We use full-spectrum fitting to derive radial velocities and spectral parameters. The high mass ratio indicates that the system underwent mass transfer in the past. We compute the orbital solution and find that it is a very close sub-giant/red giant pair on circular orbit, slightly inclined to the sky-plane. Fitting of the TESS photometrical data confirms this and suggests an inclination of i \sim 39.8 deg. The light curve and spectrum around H_alpha show signs of irregular variability, which supports ongoing mass transfer. The binary evolution simulations suggest that the binary may experience non-conservative mass transfer with accretion efficiency 0.3, and the binary will enter into common envelope phase in the subsequent evolution. The remnant product after the ejection of common envelope may be a detached double helium white dwarf (He WD) or a merger.
