A5058791758- Stellar, planetary, and galactic studies
- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Cosmology and Gravitation Theories
- Gamma-ray bursts and supernovae
- Scientific Research and Discoveries
- Astrophysical Phenomena and Observations
- Astrophysics and Star Formation Studies
- Black Holes and Theoretical Physics
- Historical Astronomy and Related Studies
- Pulsars and Gravitational Waves Research
- Spectroscopy and Chemometric Analyses
- Astronomical Observations and Instrumentation
- Nonlinear Waves and Solitons
- Cerebrospinal fluid and hydrocephalus
- History of Science and Medicine
- History and Developments in Astronomy
- Fractional Differential Equations Solutions
- Data Visualization and Analytics
- UAV Applications and Optimization
- Metaheuristic Optimization Algorithms Research
- CCD and CMOS Imaging Sensors
- Advanced Control and Stabilization in Aerospace Systems
- Dermatologic Treatments and Research
- Liver Diseases and Immunity
Badr University in Cairo
2025
National Research Institute of Astronomy and Geophysics
1998-2023
Nova Southeastern University
2022
Hackensack University Medical Center
2022
Astronomical Observatory of Capodimonte
1998-2000
We were able to accurately predict the shadow path and successfully observe an occultation of a bright star by Chiron on December 15, 2022. The Kottamia Astronomical Observatory in Egypt did not detect solid body, but we found three extinction features light curve that had symmetrical counterparts with respect central time occultation. One is broad shallow, whereas other two are sharper, maximum ∼25% at achieved spatial resolution 19 km per data point. From Wise Israel, detected caused main...
Modeling of matter bounce in $f(R,T)$ gravity has been presented with no violation the null energy condition. Only a closed universe negative pressure is allowed good agreement some recent observations which favor positive curvature. Our results agree works combination curvature and vacuum leads to non-singular bounces The stability model discussed. cosmographic parameters are developed for derived explain accelerated expansion universe.
The study of Early-Type Galaxies (ETGs) in different environments is a strong tool to understand their star formation history and evolution. Fundamental Plane (FP) ETGs has been studied the nearby universe such as groups, clusters field. We found that our sample shows good agreement with FP Coma cluster, except for scatter some galaxies. A major part due variations mass light ratio result metallicity or age trends stellar populations structural dynamical properties noticed most deviant...
A main question in astrophysics and cosmology has been the severe stability of astrophysical objects, whether a particular equilibrium configuration is stable. In this article, we study relativistic self-gravitating, hydrostatic spheres with polytropic equation state , considering structures indices illustrates results for parameters . We determined critical parameter at which mass polytrope maximum value represents first mode radial instability. For n=1 (0.5)-2.5, stable polytropes occur...
Innovation in the ground and space-based instruments has taken us into a new age of spectroscopy, which large amount stellar content is becoming available. So, automatic classification spectra became subjective last three decades due to availability observed spectral database as well theoretical spectra. In present paper, we develop an Artificial Neural Network (ANN) algorithm for automated The been applied extract fundamental parameters optical some hot helium-rich white dwarf stars by...
We present a new method for determining the age and relative contribution of different stellar populations in galaxies based on genetic algorithm. apply this to barred spiral galaxy NGC 3384, using CCD images U, B, V, R I bands. This analysis indicates that 3384 is mainly inhabited by old population (age >109 yr). Some problems were encountered when numerical simulations are used integrated color galaxy. The results show proposed algorithm can search efficiently through very large space...
In this paper, we have constructed a flat Friedmann-Robertson-Walker (FRW) cosmological model in f(R,T) gravity. The solution of Friedmann equations has been obtained assuming the quadratic equation state p=αρ+βρ2, where α and β are parameters. describes an accelerating universe with positive energy density, negative pressure constant. behaviour deceleration parameter shows that accelerates after epoch good agreement recent observations. non-conventional scenario for constant discussed.
The high mass X-ray binary system 4U 0114+65 was observed by Nustar in October 2019, and XMM-Newton August 2015. Here we performed spectral timing analysis of the observation, carry out on data. We measured spin period neutron star from both observations found a spin-up rate $\dot{p} = 1.54 \pm 0.38 \times 10^{-6} s s^{-1}$. During observation two flares occured, one occured shortly after start other near end separated long low/quiescent- state. large sudden mostly resulted accretion...
A sample of edge-on (or nearly edge-on) spiral and lenticular galaxies is selected to study the warp phenomenon in their disks. This contains 36 disk from Watanabe’s catalogue (Watanabe, 1983). We investigate existence physical relations between photometric spectroscopic parameters degree galaxies.
Abstract We find a strong correlation between the effective radius of largest early‐type galaxies in compact groups and velocity dispersion groups. The lack similar for late type is supportive so called second generation merging scenario which predicts that ellipticals should dominate internal dynamics groups, while late‐type are mainly recent interlopers still an early stage interaction with group potential.
In this paper the tree clustering technique (the Euclidean separation distance coefficients) is suggested to test how Hickson compact groups of galaxies (HCGs) are really physical groups. The method applied on 5 members only in Hickson’s catalog.
Harold Knox-Shaw (1885-1970) worked at the Helwan Observatory in Egypt from 1907 to 1924. The was equipped with a 30-inch (76 cm) reflector that financed and constructed by Birmingham industrialist, John Reynolds (1874-1949), benefit clearer skies more southerly latitude compared Britain. obtained first photograph of Halley's Comet on its 1910 perihelion passage. He also carried out morphological studies nebulae may have been identify what later became be known as elliptical galaxies...
In this paper, we introduce a novel analytical solution to Tolman-Oppenheimer-Volkoff (TOV) equation, which is ultimately hydrostatic equilibrium equation derived from the general relativity in framework of relativistic isothermal spheres. Application traditional power series expansions on solving TOV results limited physical range convergent solution. To improve convergence radii obtained solutions, combination two techniques Euler-Abel transformation and Pade approximation has done. The...
Abstract History, Maths and Astronomy are all mixed up in an innovative educational project that is being carried out the Faculty of Education Universidad de La Laguna, Spain. Students learn how to teach (to primary school students) about shape Earth, distances Moon, Sun other planets, collecting their own data with simple instrumentation and, most important, connect ideas different disciplines. The structure contents this presented, as well examples activities out.
Facial hypervascularity is a condition that manifests as erythema and edema caused by aberrant blood vessels. Often, the cause of these abnormal vessels can be attributed to previous trauma or vascular conditions such rosacea, although sometimes unknown. Pulsed dye laser (PDL) an effective treatment even when We present case 24-year-old male presenting with intermittent swelling, redness, throbbing sensations nose cheeks for past five years. Physical examination was notable prominent...