Summary

The basis of the project work is Kreiner et al. (2001) is based on TESS, KEPLER satellite telescope data and ground-based photometric observations and other ground-based survey data. The O-C change obtained from the minimum times of the interacting dual systems with the data obtained is based on the solution of the O-C diagrams created by adding the literature and other minimum times of the systems that have completed at least 2500 cycle periods. Thus, O-C diagrams of systems showing period change that can be modeled (linear, parabolic, sinusoidal and sinusoidal changes superimposed on a line or parabola) will be modeled and the physical mechanisms that cause period change for each system will be investigated. In our proposed project, it is aimed to investigate the existence of an additional object (3rd object) in close binary star systems that show occultation by using the timing method. By creating the differences (O–C: Observed – Calculated) between the observed (Observed) and calculated (Calculated) minimum times of the systems examined by the timing method with linear light elements (linear ephemeris), the remaining residues can show cyclic changes. These changes are due to the gravitational effect of the third body orbiting around this system while the components of the double star system are covering each other, so that the system moves away from us and its light reaches us a little later, or it moves closer to us and its light reaches us a little earlier. For these binary stars, the Light-Time (LTT: Light-Travel) effect can be measured and is used to investigate whether there is a third object (collateral star, exoplanet or brown dwarf) in such star systems. In order to determine whether the changes obtained from O–C diagrams are caused by additional components and/or exoplanets, the LTT signal must show a cyclic structure. Within the scope of the project, it is aimed to obtain astrophysical parameters related to additional components and/or exoplanets by developing these models. O-C solution parameters will be determined using the Ocfit program, which works with the Marcov Chain Monte-Carlo (MCMC) algorithm. An orbital stability test will be carried out for an additional object to be determined connected to the system. In the project study, O-C diagrams for all types of interacting binary systems will be analyzed and the period changes that will be found observationally will be interpreted according to the evolutionary states and types of binary systems. In addition, systems that are likely to contain additional components will be determined and presented to the literature as triple system candidates. Possible exoplanets will be suggested around eclipsing pairs, based on small amplitude changes that can be found by analyzing cyclic changes in O-C residues. Systematic ground-based observational tracking of the binary star systems to be examined within the scope of our project is required. These ground-based photometric observations will be carried out through observation projects awarded to TUBITAK National Observatory (TUG, T100 Telescope, Antalya) and Çanakkale University Ulupınar Observatory (UPO, T30, T40 Telescope). If necessary, the telescopes used by the collaboration team in Canada and Mexico, where we have international collaborations and joint studies (UNAM San Martin Observatory, Mexico and International observatories used by the Canada-based Binary Systems of South and North Project (BSN-Project) team) will also be used. Thus, it will be possible to access a large number of observation data distributed over a long time period. The project will include researchers who are experienced in the targeted research, and new students will be trained in both observation and data analysis in this field.