Zobrazeno 1 - 8
of 8
pro vyhledávání: '"F. Y. Kamal"'
Publikováno v:
Revista Mexicana de Astronomía y Astrofísica. 56:245-257
We present a photometric and astrometric analysis of the NGC 2158 cluster using Gaia DR2 and 2MASS data. The cluster age, color excess, intrinsic distance modulus and distance are calculated to be t = 2.240 ± 0.260 Gyr, E(B − V) = 0.420 ± 0.050 m
Publikováno v:
New Astronomy. 92:101727
We present an astrometric and photometric study of the young open star cluster NGC 2168 and its proposed member [NBN2015]77. NGC 2168 was investigated by combining data from both the Gaia-ESO DR2 and the 2MASS databases. The photometric analysis and
Autor:
M. A. Sharaf, Mohamed I. Nouh, H. I. Abdel-Rahman, I. A. Issa, A. S. Saad, Essam, A. Bakry, F. Y. Kamal, A. M. I. Osman
Publikováno v:
Journal of The Korean Astronomical Society. 42:71-79
In this paper, statistical distribution functions are developed for distance determination of stellar groups. This method depends on the assumption that absolute magnitudes and apparent magnitudes follow a Gaussian distribution function. Due to the l
Autor:
M. A. Sharaf, F. Y. Kamal
Publikováno v:
Astronomische Nachrichten. 324:238-241
In this paper, we developed statistical method for distance determination of a stellar group. The method depends on the assumption that, the stars scatter around a mean magnitude in a Gaussian distribution. The mean apparent magnitude of the stars is
Publikováno v:
Solar Physics. 158:383-386
A great sunspot group of October 1991 (NOAA 6891 atL = 189,B = −10) was observed, in which an eruptive flare of importance (X2.5/31B) has been reported. A Caii-line 3933 A filter was used, and during a time interval of 3 hours more than 90 frames w
Publikováno v:
Astrophysics and Space Science. 222:227-230
Sunspot observations are taken on a regular basis, and then analysed in a systematic methodology at the Dept. of Astronomy at King Abdul Aziz University (KAAU). In this article we investigate the accuracy of these observations for the period of 12 ye
Publikováno v:
Astrophysics and Space Science. 190:67-88
Results from a detailed isophotometric survey of NGC 5595, NGC 5597, NGC 5605, and NGC 7769 are given. It includes isophotic maps, luminosity profiles and ellipticity curves as well. Scanning of these galaxies was done in theB andV colours.
Publikováno v:
Astrophysics and Space Science. 190:89-117
Results about the standard photometric parameters of four galaxies are given. The equivalent and the integrated parameters defined according to de Vaucouleurs are listed. Effective values of the abovementioned ingredients, the reduced luminosity prof