Monitoring possible light-time effect in the orbital period of some eclipsing binaries at the Ankara University Observatory

A significant number of close binaries are known to be members of physically bound triple or multiple star systems. The O - C analysis technique which is based on the minima times of an eclipsing binary can reveal the light-time effect due to the presence of gravitationally bound and generally unseen close component(s) in the system. In this study we present shortly the O - C analysis results based on the light-time effect possibilities for two of the eclipsing binaries observationally followed by our group; TZ Boo and CF Tau.