Investigation of Cyclic O−C Changes in a Sample of Eclipsing Binaries

In this work we present an analysis of cyclic or pseudo-cyclic O–C behavior in a sample of 29 eclipsing binaries, selected to exhibit large-amplitude changes in O–C. We attempt to explain the period variations by: 1) the light time travel effect due to an unseen third body orbiting a system; 2) a sudden jump in the linear ephemeris caused by either variations in the mass transfer rate or CME ejections. A search for tertiary components was carried out with adaptive optics imaging for six systems exhibiting the highest amplitude in their O–C diagrams.