The Variable Velocity of Theta Carinae

Abstract

A study of the radial velocity variations of the bright, peculiar B star, theta Carinae, using published optical velocities and new IUE data, fails to confirm any of the orbital periods proposed for this system. Instead a new period of 2.203020 +- 0.000017 days is found and it is also suggested that there is a second period at about 25 days. Previously reported line variations found in the optical were not found in the IUE data. The interpretation of this system is still unclear and requires a coordinated observational effort. (SECTION: Stars)