Photometric and spectroscopic analysis of selected eclipsing binary systems

In this thesis, spectroscopic and photometric analysis of RS Sgr, AT Vul and EM Boo also known as Algol type binary stars were studied. High resolution FEROS spectra of RS Sgr and AT Vul systems, and the medium resolution UBT60 eShel spectra of EM Boo system, which is determined to contain the third component, were analyzed. Extracted spectra of the components were obtained by spectral disentangling method. The extracted spectra were used to precisely determine the temperature (Teff) and surface gravity acceleration (logg) parameters of each component in the systems. In addition, orbital parameters of the systems were obtained from radial velocities of components which were measured from spectra. For the RS Sgr and AT Vul systems, light curve analyzes were made using photometric data obtained from the literature and for EM Boo system using the 25-cm telescope (AUT25) at Akdeniz University. Precisely determined absolute parameters of the systems were determined for the first time from the simultaneous analysis of the spectral and photometric data of the systems. Absolute parameters of the systems were checked with theoretical evolution models and the evolution of the processes such as mass transfer/loss has been demonstrated with the evolution models. Due to the mass transfer between components in the RS Sgr system, the mass receiving primary component is less luminated than its mass, while the secondary component, which losesmass, isin thelargerluminatedevolutionstepthan its mass. In the AT Vul system, both components are in the large luminated evolutionary step for the abundance of solar elements. In addition, spectral analysis determined that EM Boo system contains a third component and it is a detached Algol type system. For the multiple system EM Boo, whose precise physical parameters were determined, the isochrone curves were calculated and the age of the system was determined as 9.45 Myr.