Discovery and modeling of overcontact binaries in photometric and spectroscopic sky surveysKochoska, Angela (Avtor) Zwitter, Tomaž (Mentor) Prša, Andrej (Komentor) starsclose binarieseclipsing binariesspectroscopic binariesstar atmospheresradiative transfernumerical methodsContact binaries are close binary systems whose components are in physical contact and share an atmosphere. They comprise about ~ 10-20 % of all binaries in present photometric sky surveys like Kepler and OGLE and thousands of light curves and spectra of these stars are already available, a number that is expected to increase by several orders of magnitude with new all-sky surveys like Gaia and LSST. Despite being abundant, the structure of contact binaries puzzles astronomers to this day. The inconsistencies with observations and the mere complexity of the theoretical models of mass and heat transfer in these objects have resulted in their continuous neglect in modern tools of binary star analysis. The light curve analysis is instead carried out through populating the surface of the contact envelope with blackbody radiation properties, or model atmospheres computed under assumptions that apply to single stars. This Thesis highlights the key problems and inconsistencies of contact binary modeling today and proposes a framework that serves to bridge the gap between the large influx of observational data and the lack of accurate models for the analysis of said data. The basic principles of a newly developed and freely available generalized radiative transfer code are outlined and their application to different geometries and stellar structures is discussed. The final goal of this ambitious project is the computation of model atmospheres under the correct assumptions for contact binaries for use in modern binary star analysis codes. This will enable testing of the many theoretical models at hand on high-quality data that would not only reveal the true structure and populations of contact binaries, but if applied to the large samples of data from present and future large-scale sky surveys, will also uncover fundamental aspects of their formation and evolution.20172018-01-05 07:15:03Doktorsko delo/naloga99179VisID: 87038COBISS_ID: 3163236sl