SIMBAD references

MY Cygni is a relatively bright eclipsing binary system with a slightly eccentric orbit. Tucker and collaborators found that it shows retrograde apsidal motion in contradiction with theory. Based on a new O-C diagram solution, we concluded that the apsidal motion is prograde in agreement with theory, and its period is about 1400years. The determined internal structure constant is close to the theoretically expected value. The relativistic effect is significant, being about 18% of the total apsidal motion rate.