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E. Elkholy

Publications and source records attributed to E. Elkholy.

3 recordsLinked to original sources

Light Curve Modelling and Evolutionary Status of the Short Period Binary 1SWASP J092328.76+435044

Light curve modeling for the newly discovered system 1SWASP J092328.76+435044 was carried out by using a new BVR complete light curves. A spotted model was applied to treat the asymmetry of the light curves. The output model was obtained by means of Wilson-Devinney code, which reveals that the massive component is hotter than the less massive one with about ΔT ~ 400K. A total of 8 new times of minima were estimated. The evolutionary state of the system components was investigated based on the estimated physical parameters.

astro-ph.SR

An Extensive Photometric Investigation of the W UMa System DK Cyg

DK Cyg (P = 0.4707) is a W Ursae Majoris type eclipsing binary system that undergoes complete eclipses. All the published photoelectric data have been collected and utilized to re-examine and update the period behavior of the system. A significant period increase with rate of 12.590x10-11 day/cycle was calculated. New period and ephemeris has been calculated for the system. A long term photometric solution study was performed and a light curve elements were calculated. We investigated the evolutionary status of the system using theoretical evolutionary models.

astro-ph.SR

Spectroscopic Analysis of the Double Lined Eclipsing Binary αVir

αVir is a well known double-lined spectroscopic binary with a B-type for both components. In the present paper we have analyzed a total of 90 spectra obtained through 1992-2000. Spectral analysis are based on two spectral lines H(alpha) and HeI 6678 belong to H(alpha) region. Radial velocity analysis have suggested low eccentric orbit (e=0.002) at inclination (i=81.89+-2.34) and with 4d.01422 period, semi-amplitude k1=100 km/s, mass ratio q=0.49+-0.05 and mass function f(m) =0.547. Using KOREL program for spectrum disentangling we have been able to decompose the spectrum of the system to its primary and secondary components. Synthetic spectral analysis of both the individual and disentangled spectra has been performed and yielded effective temperatures Teff= 25000+-250 K, surface gravities log g=3.75+-0.25 and projected rotational velocities (v sin i= 180+-5 km/s) for the primary, while for the secondary they are Teff = 17000+-250 K, log g = 4.0+-0.25.

astro-ph.SR