scholarly journals Modified Finch and Skea stellar model compatible with observational data

2014 ◽  
Vol 356 (2) ◽  
pp. 285-292 ◽  
Author(s):  
D. M. Pandya ◽  
V. O. Thomas ◽  
R. Sharma
2019 ◽  
Vol 79 (10) ◽  
Author(s):  
Shyam Das ◽  
Farook Rahaman ◽  
Lipi Baskey

Abstract In this work, a physically reasonable metric potential $$g_{rr}$$grr and a specific choice of the anisotropy has been utilized to obtain closed-form solutions of the Einstein field equation for a spherically symmetric anisotropic matter distribution. This class of solution has been used to develop viable models for observed pulsars. Smooth matching of interior spacetime metric with the exterior Schwarzschild metric and utilizing the condition that radial pressure is zero across the boundary leads us to determine the model parameters. A particular pulsar $$4U1820-30$$4U1820-30 having current estimated mass and radius ($$mass=1.58 M_\odot $$mass=1.58M⊙ and $$radius=9.1$$radius=9.1 km) has been allowed for testing the physical acceptability of the developed model. The gross physical nature of the observed pulsar has been analyzed graphically. The stability of the model is also discussed given causality conditions, adiabatic index and generalized Tolman–Oppenheimer–Volkov (TOV) equation under the forces acting on the system. To show that this model is compatible with observational data, few more pulsars have been considered, and all the requirements of a realistic star are highlighted. Additionally, the mass-radius (M–R) relationship of compact stellar objects analyzed for this model. The maximum mass for the presented model is $$\approx 4M_\odot $$≈4M⊙ which is compared with the realization of Rhoades and Ruffini (Phys Rev Lett 32:324, 1974).


1966 ◽  
Vol 25 ◽  
pp. 266-267
Author(s):  
R. L. Duncombe

An examination of some specialized lunar and planetary ephemerides has revealed inconsistencies in the adopted planetary masses, the presence of non-gravitational terms, and some outright numerical errors. They should be considered of temporary usefulness only, subject to subsequent amendment as required for the interpretation of observational data.


1994 ◽  
Vol 144 ◽  
pp. 567-569
Author(s):  
V. Kulidzanishvili ◽  
D. Georgobiani

AbstractThe observational data of July 11, 1991 eclipse solar corona obtained by both electropolarimeter (EP) and CCD-matrix were processed. Using these data, the solar corona photometry was carried out. The results of EP data are compared with the ones of CCD data. It must be noted here that the CCD data give us only characteristics of the inner corona, while the EP data show the features of both the inner and middle corona up to 4R⊙. Standard flattening indexϵis evaluated from both data. The dependence of the flattening index on the distance from the solar limb is investigated. The isophotes in Na and Ca lines are plotted. Based on these data some ideas and conclusions on the type of the solar corona are presented.


1976 ◽  
Vol 32 ◽  
pp. 49-55 ◽  
Author(s):  
F.A. Catalano ◽  
G. Strazzulla

SummaryFrom the analysis of the observational data of about 100 Ap stars, the radii have been computed under the assumption that Ap are main sequence stars. Radii range from 1.4 to 4.9 solar units. These values are all compatible with the Deutsch's period versus line-width relation.


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