HIPPARCOS katoloğunda yanlış kodlanmış olası örten çift yıldızların ayıklanması
Abstract
ABSTRACT Master Thesis ON THE SEPERATION OF MISS-IDENTIFIED POSSIBLE ECLIPSING BINARIES IN THE HIPPARCOS CATALOGUE İbrahim ÖZAVCI Ankara University Graduate School of Natural and Applied Sciences Department of Astronomy and Space Sciences Supervisor : Assoc.Prof. Dr. Selim O. SELAM In this thesis, a study was done about clarifying the variabilitiy type ambiguity and determining the true nature of the light variability of some HIPPARCOS satellite discoveries of DSCT (6 Scuti's), BCEP (p Cephei's), RRC ( c sub-title RRLyrae's) and P (Periodic variables but the true nature of the light variability can not determined) types in which their variability types assigned with an automated classifying procedure of HIPPARCOS mission and probably including miss-identified short-period eclipsing binaries. A working sample of HIPPARCOS discoveries of DSCT, BCEP, RRC and P types was constructed with the aid of selection criteria described in this work. Initially, the true pulsating variables in this sample were separated with their deviations from the Log P - (B-V) calibration for WUMa type systems defined by Rucinski and Duerbeck (1997). Afterwords, the variability type discrimination for the remaining eclipsing binaries candidates was done by following the technique of Selam (2004). After these processes, the number eclipsing binary candidates reduced to 27 for the working sample and as a result all of them turned out to be plausible contact binaries. The light curves of 25 of them based on HIPPARCOS photometry were analyzed with the aid of Rucinski (1993b) method and first approximation to their basic geometrical elements (namely, q mass ratio, / degree of contact, and / orbital inclination angle) were determined. Among these systems, new photometric observations were obtained at the TÜBİTAK National Observatory (TUG) for DN Boo and FT UMa and the relevant B, V, R light curves were analysed by using 2003 version of the Wilson-Devinney Code (WD-2003). 2005, 69 pages Key Words: Eclipsing Binary Stars, W UMa-type Binaries, (3 Lyr-type Binaries, DN Boo, FT UMa 11