EDP Sciences
Free access
Volume 498, Number 3, May II 2009
Page(s) 821 - 823
Section Stellar structure and evolution
DOI http://dx.doi.org/10.1051/0004-6361/200911864
Published online 01 April 2009
A&A 498, 821-823 (2009)
DOI: 10.1051/0004-6361/200911864

Research Note

On the apsidal motion of MY Cygni

M. Wolf

Astronomical Institute, Faculty of Mathematics and Physics, Charles University Prague, 180 00 Praha 8, V Holešovičkách 2, Czech Republic
    e-mail: wolf@cesnet.cz

Received 17 February 2009 / Accepted 24 February 2009

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 1400 years. 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.

Key words: stars: binaries: eclipsing -- stars: individual: MY Cyg -- stars: fundamental parameters

© ESO 2009