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NEW CCD OBSERVATIONS AND THE FIRST PHOTOMETRIC STUDY OF THE CONTACT BINARY AP UMI
N. S. AWADALLA,M. A. HANNA,M. N. Ismail,I. A. Hassan,M. A. Elkhamisy 한국천문학회 2016 Journal of The Korean Astronomical Society Vol.49 No.3
We obtain the first complete CCD light curves (LCs) of the contact binary AP UMi in the VRI bands and analyzed them by means of the PHOEBE code. A spotted model is applied to treat the asymmetry in the LCs. The LC morphology clearly shows the O'Connell effect and the solution shows an influence of star spots on both components. Such effect of star spots is common between the RS CVn and W UMa chromospherically active stars. Based on the obtained solution of the LCs we investigate the evolutionary state of the components and conclude that the system is a pre-intermediate contact binary ($f=0.29$) with mass ratio $q=0.38$, and it is an A-type W UMa system where the less massive secondary component is cooler than the more massive primary one.} We obtain the first complete CCD light curves (LCs) of the contact binary AP UMi in the VRI bands and analyzed them by means of the PHOEBE code. A spotted model is applied to treat the asymmetry in the LCs. The LC morphology clearly shows the O'Connell effect and the solution shows an influence of star spots on both components. Such effect of star spots is common between the RS CVn and W UMa chromospherically active stars. Based on the obtained solution of the LCs we investigate the evolutionary state of the components and conclude that the system is a pre-intermediate contact binary ($f=0.29$) with mass ratio $q=0.38$, and it is an A-type W UMa system where the less massive secondary component is cooler than the more massive primary one.
ABSOLUTE PARAMETERS AND MASS-RADIUS-LUMINOSITY RELATIONS FOR THE SUB-TYPES OF W UMα BINARIES
AWADALLA N. S.,HANNA M. A. The Korean Astronomical Society 2005 Journal of The Korean Astronomical Society Vol.38 No.2
The authors have assembled a sample of 80 W UMa binary systems (42 W-subtype and 38 A-subtype) whose light curves have all been solved by means of the recent W-D code and combined with up-to-date radial velocity solutions. The absolute parameters (masses, radii and luminosities) have been derived (without any constraint on the physical parameters). The main results of this paper are: (1) the mass-luminosity relations for both W&A-subtypes. as well as for all W UMa contact binaries have been shown, (2) the mass-radius relations have been found for both subtypes, (3) some remarks on the evolution status have been presented.
Girges, M.M.,El-Zahab, Abou M.M.,Hanna, M.A. The Pharmaceutical Society of Korea 1988 Archives of Pharmacal Research Vol.11 No.3
A new series of substituted phenazone derivatives has been prepared through a series of reactions that are illustrated in Scheme I. The antibacterial and antineoplastic activities of the prepared compounds were evaluated. While none of the synthesized products showed marked antibacterial activity, all of them possessed a significant antitumor effect.
ORBITAL PERIOD VARIATION STUDY OF THE ALGOL ECLIPSING BINARY DI PEGASI
Hanna, M.A.,Amin, S.M. The Korean Astronomical Society 2013 Journal of The Korean Astronomical Society Vol.46 No.4
We discuss the orbital period changes of the Algol semi-detached eclipsing binary DI Peg by constructing the (O-C) residual diagram via using all the available precise minima times. We conclude that the period variation can be explained by a sine-like variation due to the presence of a third body orbiting the binary, together with a long-term orbital period increase (dP/dt=0.17 sec/century) that can be interpreted to be due to mass transfer from the evolved secondary component (of rate $1.52{\times}10^{-8}M_{\odot}/yr$) to the primary one. The detected low-mass third body ($M_{3min.}=0.22{\pm}0.0006M_{\odot}$) is responsible for a periodic variation of about 55 years light time effect. We have determined the orbital parameters of the third component which show a considerable eccentricity $e_3=0.77{\pm}0.07$ together with a longitude of periastron ${\omega}_3=300^{\circ}{\pm}10^{\circ}$.
Resonant Raman Study on the Nitrogen-Induced Electronic States in GaAs$_{1-x}$N$_{x}$
M. J. Seong,A. Mascarenhas,정현식,J. F. Geisz,M. C. Hanna,윤석현 한국물리학회 2004 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.45 No.1
Nitrogen-induced electronic states, encompassing E0 through E+, in GaAs1%) have been probed using resonant Raman scattering. We have observed strong Raman intensity resonance enhancement for the L and X zone boundary phonons as well as the zone center phonons for excitations near the E+ transition, which provides unambiguous evidence of signicant L and X components in the wave function of the nitrogen-induced E+ state in GaAs1 The resonant Raman scattering prole for the asymmetric line-width broadening of the LO phonon exhibits two distinct maxima attributed to states arising from a splitting of the quadruply degenerate conduction band near the L-point.