Kh. F. Khaliullin

Apsidal motion in the eclipsing binary AS Cam

AbstractMulti-colourWBVR photoelectric observations of the eclipsing binary AS Cam have been carried out and the photometric elements, absolute dimensions, and the angular velocity of a periastron motion (

Photometric elements, apsidal motion, and a third body in the eclipsing binary HP Aur

\mathop \omega \limits^ \cdot _{obs}

Orbital-period variations in the eclipsing binary Y Cam

) are determined. The obtained value of

Apsidal motion in the eclipsing binary GG Ori

\mathop \omega \limits^ \cdot _{obs}

Apsidal motion and the third-body problem in the binary HS Her

is almost three times smaller than that theoretically predicted.

Photometric elements and apsidal motion of the eclipsing binary ES Lac

An analysis of fifteen-year photoelectric observations of DI Herculis shows that the upper estimate for the relativistic part of apsidal motion in this binary system is almost three times lower than the theoretical value. The total observed angular velocity of apsidal rotation is 0.°0124 yr−1. The relativistic part is less than 0.°008 yr−1 instead of 0.°023 yr−1 required by the theory.