Yazar "Akan, MC" seçeneğine göre listele

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    Öğe
    A binary star with a ? Scuti component
    (Univ Chicago Press, 2003) Soydugan, E; Demircan, O; Akan, MC; Soydugan, F
    New photometric observations of the Algol-type binary system AB Cassiopeiae were obtained in B and V filters during the 2001-2002 observing season at Ege University Observatory. As expected, the new light curves of the system, which were analyzed using the Wilson-Devinney code, exhibit short-period oscillations due to pulsation of the primary component. A photometric q-value search was performed, and the mass ratio of the system was found to be 0.19. The residuals from the observed-minus-computed light curves of the system reveal the pulsation light curves of the primary component. From the clear cycles of the pulsations in the light curves, we determined 21 new times of maximum light. The frequency content was investigated by using the Period98 program. Although the amplitude variation may suggest multiple periodicity in the pulsations, the power spectrum shows that only one frequency is significant; the remaining frequencies are probably not statistically significant. A multisite campaign is needed in order to study the reliability of the other pulsation modes.
  • [ X ]
    Öğe
    The connection between the pulsational and orbital periods for eclipsing binary systems
    (Oxford Univ Press, 2006) Soydugan, E; Ibanoglu, C; Soydugan, F; Akan, MC; Demircan, O
    Considering a sample of 20 eclipsing binary systems with delta Scuti type primaries, we discovered that there is a possible relation among the pulsation periods of the primaries and the orbital periods of the systems. According to this empirical relation, the longer the orbital period of a binary, the longer the pulsation period of its pulsating primary. Among the sample, the masses of the secondaries and the separations between the components are known for eight systems for which a log P-puls versus log F (the gravitational pull exerted per gram of the matter on the surface of the primaries by the secondaries) diagram also verifies such an interrelation between the periods. So, as the gravitational force applied by the secondary component onto the pulsating primary increases, its pulsation period decreases. The detailed physics underlying this empirical relation between the periods needs further confirmation, especially theoretically. However, one must also consider the fact that the present sample does not contain a sufficiently large sample of longer period (P > 5 d) binaries.