Third body effect in eclipsing binary system and some sample analysis

In this thesis, we studied third body effect of five eclipsing binary systems (RR Dra, RW Leo, AH Tau, BO Vul and XZ UMa). Observations of these systems were made and new minimum times were obtained by Kwee Van Woerden (1956) method. Minima times of the systems were collected from the literature and O-C diagrams were plotted. 3T programme of Pribulla (2005) was used for analysis. The parameters of the third bodies were obtained by analysis. O-C variations of these systems contain parabolic and periodic changes. These changes show us presence of a probable third bodies and mass trasfers. Finally, parameters of third bodies were obtained and masses of the third bodies was calculated.