论文标题
WR 63：多系统（O+O）+WR？
WR 63: A multiple system (O+O)+WR ?
论文作者
论文摘要
狼射线（WR）恒星WR 63的光谱包含两个不同的恒星的光谱线，它们显示了〜4.03 d期间幅度约为160和〜225 km/s的规则径向速度（RV）变化。光曲线显示了两种狭窄的日食，在RV变化的同一时期，在同一时期深度为0.2 mag。另一方面，我们的数据显示WR光谱线没有显着的RV变化。这些发现与WR 63兼容，是由两个非相互作用的晚期O恒星组成的三重系统，该恒星在大于1000天的周期中绕着WR星绕。 WR光谱线质量变异性的幅度达到了线强度的7-8％，似乎与0.04 MAG周期光度变化有关。大风密度结构是这种可变性的可能起源，但是我们的数据不足以验证这一点。我们的分析表明，如果三颗星被绑定，它们将与约5.9 +/- 1.4 Myrs的年龄相同。与恒星的距离估计为3.4 +/- 0.5 kpc。它们的动态质量为14.3 +/- 0.1和10.3 +/- 0.1 m_sol。使用旋转的单星进化轨道，我们估计它们的初始质量分别为18 +/- 2和16 +/- 2 m_sol，分别为初级和次级。将来需要定期的光谱监测来检测WR恒星的RV变化，这将证明其重力与近距离O+OB系统结合并确定其质量。
The spectrum of the Wolf-Rayet (WR) star WR 63 contains spectral lines of two different O stars that show regular radial velocity (RV) variations with amplitudes of ~160 and ~225 km/s on a ~4.03 d period. The light-curve shows two narrow eclipses that are 0.2 mag deep on the same period as the RV changes. On the other hand, our data show no significant RV variations for the WR spectral lines. Those findings are compatible with WR 63 being a triple system composed of two non-interacting late O stars orbiting a WR star on a period larger than 1000 days. The amplitude of the WR spectral line-profile variability reaches 7-8% of the line intensity and seems related to a 0.04 mag periodic photometric variation. Large wind density structures are a possible origin of this variability, but our data are not sufficient to verify this. Our analysis shows that, should the three stars be bound, they would be coeval with an age of about 5.9+/-1.4 Myrs. The distance to the O stars is estimated to be 3.4+/-0.5 kpc. Their dynamical masses are 14.3+/-0.1 and 10.3+/-0.1 M_sol. Using rotating, single star evolutionary tracks, we estimate their initial masses to be 18+/-2 and 16+/-2 M_sol for the primary and the secondary, respectively. Regular spectral monitoring is required in the future to detect RV variations of the WR star that would prove that it is gravitationally bound to the close O+OB system and to determine its mass.
