In this paper, photometric analysis of two short period group of the eclipsing binaries (RS CVn); RT And and BH Vir is presented. New physical and geometric parameters were obtained by performing two computer modeling. The first model is software package PHOEBE based on the Wilson–Devinney method, and the second is Binary Maker 3 (BM3).Our results are in good agreement with those obtained using the same modeling.
Pulsar stars divided into two types depending on the periods of rotation, normal
emission Pulsar and Millisecond pulsars (MSPs). In this paper, the effect of the
strong magnetic field on the thermal emission in Millisecond pulsar stars is
concentrated. Also the luminosity spin down (Lsp) are calculated depends on the
periods (P), and Period derivative (
P
) for sample stars which were adopted. The
relation between internal and surface magnetic field is illustrated. The model that
which adopted is Hallo Cone Model (HCM)). The total magnetic dipole radiation
power (heating power Wh) of all super fluid neutrons in MSPs stars is calculated.
For sample stars of MSPs , the value of transition period (Ptr) was d
The autocorrelation function calculations have been carried out on photon-limited computer-simulated images of binary stars that recorded through kolmogorov atmospheric turbulence. The effect of the parameters of photon limited binary star on the variation of signal to noise, signal to background ratios, number of images that processed and the magnitude of binary stars are studied and mathematic equations are given to investigate this effect. The result indicates that signal to background ratio of photon limited images of a binary star is independent of the total number of recorded photons.
The structure and composition of the stellar population in the surface brightness galaxy Ic 467 is studied using BVR CCD photometry. The observations were obtained on the 1.88m optical telescope of Kottamia Astronomical Observatory, KAO, Egypt. A two-dimensional decomposition of the galaxy bulge and disk components is carried out. A powerful star forming region is observed near the galactic center. Based on the positions of the various components of the galaxy in two color diagrams and the surface brightness of the eastern arms in V filter is brighter than the western arm. From the observations, the surface brightness profiles, Ellipticity profiles, position angle profiles and color indices profiles are described and studied.
A specific, sensitive and new simple method was used for the determination of methyldopa in pure and pharmaceutical formulations by using continuous flow injection analysis. This method is based on formation of ion pair compound between methyldopa and potassium hexacyanoferrate in acidic medium to obtain a yellow precipitate complex using long distance chasing photometer (NAG-ADF-300-2). The linear range for calibration graph was 0.05-35 mmol/L for cell A and 0.05-25 mmol/L for cell B, and LOD 1.4292 µg /200 µL for both cells with correlation coefficient (r) 0.9981 for cell A and 0.9994 for cell B, RSD% was lower than 0.5 % for n=8 for. The results were compared with classical method UV-Spectrophotometric at λ max=280 nm and turbi
... Show MoreGlitches are sudden increases in the rotational frequency (ν) of a neutron star.
Glitches usually occur as fractional increase in the frequency of the order of ⁄
= - .In this work we study the glitch in normal and magnetar pulsar stars,
glitches are small or absent in the millisecond pulsar star because it is old star
whereas the weak glitch activity of young pulsars by the fact that their internal
temperatures are still too high for the crust to store a large stress .The results showed
that NART (pulsed emission only at infrared) normal pulsar has more glitches than
AXP (Anomalous X-ray Pulsar) and HE (Spin-powered pulsar with pulsed emission
from radio to infrared or higher frequencies) stars, as the same tim
A newly developed analytical method characterized by its speed and sensitivity for the determination of metformin-HCl via the formation of complex for metformin-HCl-OH--copper(II) ion from the gel bead system by continuous flow injection analysis. The method is based on the imbedded copper(II) ion in the gel bead structure can be used in the reaction for the formation of red –magneta colour complex(λmax. =530nm) formed by direct reaction of the drug with the released copper (II) ion from the gel bead in alkaline medium. Linear dynamic range for the absorbance versus metformin concentration was 0.001-1 mmol.L-1 while C.O.D was (r2% =95.33%) . The L.O.Q was 0.868mmol.L-1.L.O.D (S/N=3)=0.5μmol.L-1 from the step wise dilution for the min
... Show MoreIn this study, two lenticular galaxies (NGC 2577, NGC 4310) have been chosen to study their morphological and photometric properties, by using The [1]IRAF ISOPHOTE ELLIPSE task with griz-Filters. Observations are obtained from the Sloan Digital Sky Survey (SDSS) which are reach now to the Data Release (DR14). The data reduction of all images (bias and flat field) have been done by SDSS pipeline. The surface photometric investigations were performed like the total magnitude, together with isophotal contour maps, Surface brightness profiles and a bulge/disk decomposition of the images of the galaxies, although the disk position angle, ellipt
... Show MoreWe have carried out multi color CCD surface photometry on the spiral galaxies NGC 4800 and NGC 2715 using 1.88 m optical telescope of Kottamia Astronomical Observatory. From these observations, the surface brightness, Ellipticity, position angle and color indices profiles are studied. Stellar populations in different regions of the galaxies are analyzed using color indices diagrams. We found that the galaxy NGC 4800 has a diffuse bright nuclear region and the asymmetry of the bar is due to the nonuniform distribution of dust in the galaxy. The color indices of the western inner spiral arm coincide with the corresponding mean color indices of the bar indicates that the stellar population of the bar is the same as that of the western spira
... Show MorePulsar stars are rotating Neutron stars can be divided into two types Millisecond and Normal Pulsars. In this work the magnetic field are concentrated depends on the period (P), and Period derivative (P) for a sample Normal, Millisecond and Radio stars which adopted. In addition, the values of spin down luminosity and Heating rate are determined by depending on (Ostriker and Gunn) model. The results showed that older Millisecond define as having greater ages specified how long pulsars lives at that ages very long period pulsars to be observable have particularly large surface magnetic field. The results indicate that spin down of luminosity for Millisecond and Normal star must due to the main energy loss rotation axis to align with magne
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