Bally Ribbon Mills (United States)

ST Carinae is an eclipsing binary with a period of 0.d90165 which is believed to consist of an A0V primary and a secondary of type F5-8IV. About 900 observations inUBV, made by Somerville in 1963 but unreduced at that time, are presented. The Wood model is used to obtain orbital elements, and four different solutions of the light curves are presented. These are also computed with the solutions obtained by previous investigators of this system. The solutions indicate a reasonably consistent geometry, but there is still substantial uncertainty with regard to the mass-ratio and dynamical status of ST Car. The possibility exists that ST Car is in the initial and rapid stage of mass exchange in which the primary component fills its Roche lobe and is losing mass to its companion. The two components of ST Car appear to be of normal dimensions, but additional work is needed to clarify the exact status of this system.