Light curve of V945 Cen in Geneva photometry

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{deg}. 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.