2000A&A...354..904R

In the present study the (O-C) diagram of the eclipsing binary X Tri is used to study its orbital period behaviour. From our analysis, which is based on the description of the (O-C) diagram using weighted, high-order polynomials, it is shown that the period changes of X Tri (at least those after 1949) can be explained as due either to magnetic activity cycles or to a third companion on the subgiant G3IV cool secondary component. The elements of this hypothetical third body were computed and from their values it was found that it cannot coincide with the already known, visual companion. Moreover, if the period variations of X Tri are coming from the magnetic activity of the subgiant component of the binary, the subsurface magnetic field was found to be equal to 8.77kG.