In this work we present results of analysis of the O-C behaviour for 79 eclipsing binary systems selected from the Kreiner's database. These systems show long time scale, possibly cyclic, modulations of their orbital periods on the timescale of a few years to several decades. We consider two possibilities to explain the observed O-C changes: (1) the Light Time Travel Effect due to the presence of a third body in the system, and (2) the Applegate effect, in which orbital period modulation is caused by cyclic changes of gravitational quadrupole momentum when a star goes through its magnetic activity cycles. Within the former explanation, the orbital parameters of a hypothetical third body are fitted using the Monte Carlo method and the lower mass limit for the third companion is calculated. As a result, we derived that in 21 cases the mass of the third body exceeds the Neutron Star mass limit.
keywords in English:
chromospheres, eclipsing binaries, magnetic field
number of pulisher's sheets:
0,35
affiliation:
Wydział Fizyki, Astronomii i Informatyki Stosowanej : Instytut – Obserwatorium Astronomiczne