Apsidal motion in eccentric eclipsing binary WW Camelopardalis

Abstract

WW Camelopardalis is a relatively bright eclipsing binary system with a slightly eccentric orbit. A dozen of its new eclipse times were measured as part of our long-term observational project of eccentric eclipsing binaries. Based on a new solution of the current O – C diagram, we found for the first time an apsidal motion in good agreement with theory. Its period is about 370 ± 50 years. The determined internal structure constant is close to the theoretically expected value. The relativistic effect is significant, being about 13% of the total apsidal motion rate.