V945 Cen Geneva light curves

A detailed analysis of multicolour Geneva photometry and high-resolution echelle spectroscopy of the B8.5V star V945 Cen (HD 112409, V=5.2mag) whose short-term periodic variability was first detected from the HIPPARCOS data, led to the finding that the object is an ellipsoidal variable and a close double-lined spectroscopic binary with a 0.6496d orbital period and a circular orbit. The components have spectral types B7 and B8.5 and are both main-sequence objects. The system is detached but close to a contact configuration and is observed at an inclination of ∼23-24°. A notable finding is that the optical spectrum also contains a third system of spectral lines corresponding to a late B spectral type that remained stationary during the 5 days of spectral observations. From several independent lines of reasoning, we tentatively conclude that the third spectrum belongs to a real third body in the system. However, the possibility that it instead originates in circumbinary gas cannot be excluded completely, and additional spectral and interferometric observations are required to help us determine its origin conclusively.

对B8.5V型视星等为5.2等的B8.5V星V945 Cen（HD 112409）的多色日内瓦光度学和高清分光级联光谱学进行了详尽分析。该星短期周期性变动的首次发现源于HIPPARCOS数据，研究结果揭示该天体为一椭圆变星，且为近距离双线分光双星系统，其轨道周期为0.6496日，轨道为圆形。两子星的光谱类型分别为B7型和B8.5型，均为主序星。该系统虽为分离型，但接近接触配置，观测到的倾角约为∼23-24°。一个引人注目的发现是，光学光谱还包含一个对应于晚期B型光谱类型的第三光谱系统，该系统在为期5天的光谱观测期间保持稳定。从多个独立推理线索出发，我们暂定该第三光谱属于系统中的真实第三体。然而，该光谱可能源于环双星气体亦不能完全排除，因此需要进一步的光谱和干涉观测来帮助我们最终确定其起源。