Yazar "Zejda, M." seçeneğine göre listele

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    Öğe
    Absolute dimensions and apsidal motion of the eccentric binary V731 Cephei
    (Oxford Univ Press, 2008) Bakis, V.; Zejda, M.; Bulut, I.; Wolf, M.; Bilir, S.; Bakis, H.; Demircan, O.
    A detailed analysis of new and existing photometric, spectroscopic and spatial distribution data of the eccentric binary V731 Cep was performed. Spectroscopic orbital elements of the system were obtained by means of cross-correlation technique. According to the solution of radial velocities with UBVRc and I-c light curves, V731 Cep consists of two main-sequence stars with masses M-1 = 2.577 (0.098) M-circle dot, M-2 = 2.017 (0.084) M-circle dot, radii R-1 = 1.823 (0.030) R-circle dot, R-2 = 1.717 (0.025) R-circle dot and temperatures T-eff1 = 10700 (200) K, T-eff2 = 9265 (220) K separated from each other by a = 23.27 (0.29) R-circle dot in an orbit with inclination of 88 degrees.70 (0.03). Analysis of the O-C residuals yielded a rather long apsidal motion period of U = 10000 (2500) yr compared to the observational history of the system. The relativistic contribution to the observed rates of apsidal motion for V731 Cep is significant (76 per cent). The combination of the absolute dimensions and the apsidal motion properties of the system yielded consistent observed internal structure parameter (log (k) over bar (2,obs) = -2.36) compared to the theory ( log (k) over bar (2,theo) = -2.32). Evolutionary investigation of the binary by two methods (Bayesian and evolutionary tracks) shows that the system is t = 133(26) Myr old and has a metallicity of [M/H] = -0.04(0.02) dex. The similarities in the spatial distribution and evolutionary properties of V731 Cep with the nearby (rho similar to 3 degrees.9) open cluster NGC 7762 suggest that V731 Cep could have been evaporated from NGC 7762.
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    Öğe
    Northern Binaries in the Evrena Project
    (Cambridge Univ Press, 2012) Bakis, V.; Hensberge, H.; Zejda, M.; de Cat, P.; Yilmaz, F.; Bloemen, S.; Svoboda, P.
    In the framework of the EVRENA project, high-resolution spectra. of northern eclipsing close binaries in stellar groups are obtained with the HERMES Echelle spectrograph at the Mercator telescope (Roque de los Muchachos Observatory). This contribution gives the first results on DV Camelopardalis.
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    Öğe
    Photometric and spectroscopic study of the eclipsing binary GSC 4288 0186
    (Astronomical Soc Pacific, 2007) Bakis, V.; Bakis, H.; Budding, E.; Demircan, O.; Zejda, M.
    First complete BVRI light curves and radial velocity measurements of the recently discovered eclipsing binary GSC 4288 0186 are presented. Analyses of the light curves, together with spectroscopic data show that the system is a double-lined detached binary with an eccentric orbit. We determined the preliminary values of the absolute elements of this eclipsing binary and presented here.