We have conducted an optical long-term monitoring survey of the majority of dwarf galaxies in the Local Group, with the Isaac Newton Telescope (INT), to identify the long period variable (LPV) stars. LPV stars vary on timescales of months to years, and reach the largest amplitudes of their brightness variations at optical wavelengths, due to the changing temperature. They trace stellar populati...

star identification is one of the most important stages in attitude determination with star trackers. this can be performed using matching algorithms between observed stars and a master star catalogue. the main challenge in this approach is to provide a fast and reliable identification algorithm that is sufficiently robust in different pointing views of the star tracker optical system in the sp...

The linear adiabatic pulsation-periods of Mira variable stars have been derived. Approximately 2701[1]models were calculated for M = 0.7 MΘ to 2 MΘ stars with radii from 180 RΘ to 340 RΘ and luminosities from 2800 LΘ to 10,000 LΘ. The chemical composition of all models is (X,Z) = (0.7,0.02). From the result of this study, linear relations on Luminosity-Period-Mass relationship and luminosity-pe...

the linear adiabatic pulsation-periods of mira variable stars have been derived. approximately 2701[1]models were calculated for m = 0.7 mθ to 2 mθ stars with radii from 180 rθ to 340 rθ and luminosities from 2800 lθ to 10,000 lθ. the chemical composition of all models is (x,z) = (0.7,0.02). from the result of this study, linear relations on luminosity-period-mass relationship and luminosity-pe...

In this paper, we investigate the usage of machine learning in the detection and recognition of double stars. To do this, numerous images including one star and double stars are simulated. Then, 100 terms of Zernike expansion with random coefficients are considered as aberrations to impose on the aforementioned images. Also, a telescope with a specific aperture is simulated. In this work, two k...

in the present work, we have obtained the equation of state for neutron star matter considering the in uence of the ferromagnetic and antiferromagnetic spin state. we have also investigated the structure of neutron stars. according to our results, the spin asymmetry stiens the equation of state and leads to high mass for the neutron star.

‎In this work, we review the formalism which would allow us to model magnetically deformed neutron stars. We study the effect of different magnetic field configurations on the equation of state (EoS) and ‎the ‎structure of such stars. ‎For this aim‎, the EoS of magnetars is acquired by using the lowest order constraint variational (LOCV) method ‎‎and ‎employing‎ the AV18 potential‎.‎...

An extended star is a tree which has only one vertex with degree larger than two. The -center problem in a graph  asks to find a subset  of the vertices of  of cardinality  such that the maximum weighted distances from  to all vertices is minimized. In this paper we consider the -center problem on the unweighted extended stars, and present some properties to find solution.