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International Journal of Astronomy and Astrophysics (IJAA) is an international scientific journal dedicated to the publication and public discussion of high quality original research in all the fields of astrophysics and space sciences and related technology. All the manuscripts must be prepared in English and are sub…
Dipo Mahto, Rama Nand Mehta, Neeraj Pant, Raj Kumar Sah
The present work discusses the derivation of the formula for the change in energy of non-spinning black holes with respect to the change in mass (d E /d M ), which gives a constant quantity equal to 8.9998 x 10 16 Joule/kg in both categories of X-ray binaries…
Mustafa Bozkurt, Tulun Ergin, Murat Hudaverdi, Enise Nihal Ercan
Chandra X-ray Observatory and Fermi Gamma Ray Space Telescope analysis of young supernova remnants (SNRs) Cassiopeia A (Cas A) and Tycho were performed to understand the nature of the high energy emission from SNRs and to observationally test the diffuse shoc…
Leilei Jia
Beginning with a Lagrangian, we derived an approximate relativistic orbit equation which describes relativistic correc tions to Keplerian orbits. The critical angular moment to guarantee the existence of periodic orbits is determined. An approximate relativis…
Jacques P. Vallée
Recent advances in the position and shape of each spiral arm in the Milky Way (pitch angle, shape, number, inter - arm separation at the Sun) are evaluated and compared, and a statistical analysis yields an updated idealized Galactic map. Earlier tabular resu…
Gordon Liu
Let the coordinate system x i of flat space-time to absorb a second rank tensor field Φ ij of the flat space-time deforming into a Riemannian space-time, namely, the tensor field Φ uv is regarded as a metric tensor with respect to the coordinate system x u .…
Yasusada Nambu
We investigate image formations in gravitational lensing systems using wave optics. Applying the Fresnel-Kirchhoff diffraction formula to waves scattered by a gravitational potential of a lens object, we demonstrate how images of source objects are obtained d…
Guoqiang Ding, Chunping Huang, Jinlu Qu
Using the data from the Proportional Counter Array on board theRossi X-Ray Timing Explorersatellite, we study the orbital modulation for the spectrum and mass accretion rate of Cir X-1 during its two orbital periods. We use a model consisting of a blackbody,…
Javier Bootello
The relativistic precession of Mercury -43.1 seconds of arc per century, is the result of a secular addition of 5.02×10 -7 rad. at the end of every orbit around the Sun. The question that arises in this paper, is to analyse the angular precession at each sing…
Abhas Mitra
When one presumes that the gravitational mass of a neutral massenpunkt is finite, the Schwarzschild coordinates appear to fail to describe the region within the event horizon (EH), of a Schwarzschild Black Hole (SBH). Accordingly, the Kruskal coordinates were…
Raul G. E. Morales, Carlos Hernández
Cyanopolyynes (H[C≡C] n -CN or HC 2n+1 N, where n = 1, 2, 3, …, n) are commonly observed in the interstellar medium (ISM) as well as in the envelopes of carbon-rich stars. These linear molecular structures can be well described with a one-dimensional conducti…
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International Journal of Astronomy and Astrophysics (IJAA) is an international scientific journal dedicated to the publication and public discussion of high quality original research in all the fields of astrophysics and space sciences and related technology. All the manuscripts must be prepared in English and are sub… All articles are open access under a CC BY 4.0 licence, with authors retaining copyright.
Authors submit their manuscript, metadata, and declarations through the portal. There is no submission fee.
The editorial office screens the manuscript for scope, completeness, and formatting before assigning a handling editor.
At least two independent reviewers evaluate the manuscript under single-blind review. Where revisions are required, authors respond point by point.
On acceptance the article processing charge is invoiced and the CC BY 4.0 copyright handover is signed.
The article is copyedited, typeset, and given a DOI, then publishes open access with a permanent link.
Manuscripts must be original and not under consideration elsewhere. Submit in Microsoft Word or LaTeX with figures at 300 dpi minimum. Structure research articles as Abstract, Introduction, Methods, Results, Discussion, and References.
Use the journal's numbered (Vancouver) reference style. Cite sources consecutively in the order they appear, and ensure every reference is complete and retrievable.
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