Supervisors info:
Κοσμάς Γαζέας, Λέκτορας Παρατηρησιακής Αστροφυσικής, Τμήμα Φυσικής, Εθνικό και Καποδιστριακό Πανεπιστήμιο Αθηνών
Summary:
The current thesis focuses on the study and disentangling of physical and orbital characteristics of the systems V994 Her and 1SWASP J093010.78+533859.5. They are both quadruple stellar systems, consisted of two eclipsing binaries, whose members mutually eclipse each other. The first one includes two detached binaries, while the second one a detached and a contact binary. At the present study we use photometric data from the 2014 and 2013 record of Gerostathopouleio University of Athens Observatory (UOAO) for the systems V994 Her and 1SWASP J093010.78+533859.5, respectively. Combining the above observations with the available bibliographic data between the years 1997-2015 and 2008-2013, we conducted a study at the optical wavelengths (B, V, R, I filters) through phase diagrams and more particularly through their flux variability. With the proper adjustment of the physical and orbital parameters we model the flux variability using numerical methods. This modeling procedure takes place in three stages, using specialized software of numerical simulation of the Wilson-Devinney code and more specifically the methods LC (Light Curve), DC (Differential Corrections) and MC (Monte Carlo). As a following step, we construct the O-C diagrams of the minima timings of each system and we analyze the changes of the orbital parameters by adjusting theoretical curves, while interpreting their physical meaning. For this purpose, a specialized code in Matlab environment is used, that takes into account the Light Time Effect (LITE). With the Newton numerical method we establish an optical presentation of the orbits and observed velocities for each binary, after building an accurate code in Matlab environment. Finally, we study the evolution and we carry out a comparative study of the physical and orbital characteristics of the six in total known quadruple eclipsing systems in the universe.
Keywords:
Photometry, quadruple eclipsing binaries, O-C diagrams, magnetic activity
