Search Publications
Implications of Photon-Axion Oscillations on X-Ray Observations of the Coma Cluster
Pulatova, N.; Tugay, A.; Zadorozhna, L. +3 more
Axion-like particles (ALPs) emerge as predictions from various extensions of the Standard Model, standing out as plausible candidates for dark matter. Axions are thought to be produced when light passes through regions of magnetic fields. This positions astrophysical environments as prime sites for their production and subsequent detection. Howeve…
The Study of X-Ray Spectrum of Coma Galaxy Cluster
Pulatova, N.; Tugay, A.; Zadorozhna, L. +4 more
The X-ray spectrum of the Coma galaxy cluster was studied using the data from the XMM-Newton observatory. We combined 7 observations performed with the MOS camera of XMM-Newton in the 40' × 40' region centered at the Coma cluster. The analyzed observations were performed in 2000-2005 and have a total duration of 196ksec. We focus on the analysis o…
RT Vir - A Semiregular Star With Maser Emission: Mathematical Modelling of Optical Variability
Andronov, I. L.; Kudashkina, L. S.
The historical light curve of the semiregular pulsating star RT Vir (SRb, Sp M8III) with a maser emission is analyzed based on the AAVSO database. The star is extensively studied in the IR, radio and the optical ranges. The value of the period from the CCVS (155d) conflicts with some observational data. Signs of a systematic variability were also …
Fon Dushanbe Catalogue. Results of Processing in the Tycho-2 System
Andruk, V. M.; Protsyuk, Yu. I.; Yuldoshev, Q. +2 more
In the Tycho-2 catalogue system the processing of 1529 photographic plates of the FON Dushanbe project from the collection of the Institute of Astrophysics of the National Academy of Sciences of Tajikistan was completed. The photographic plates with the size of 8°×8° (30x30 cm) were exposed in the zones from -8° to + 84° in the period of 1985-1992…
High-Resolution Spectroscopy of the B[e] Star MWC 645
Miroshnichenko, A. S.; Manset, N.; Zharikov, S. V. +4 more
Optical high-resolution spectroscopic observations of the emission-line star MWC645 are presented. The spectrum exhibits strong variable double-peaked Balmer emission lines as well as low-excitation emission lines of FeII, [FeII], and [OI] which are signatures of the B[e] phenomenon, while lines of helium have not been found. In addition to the em…
Early Kyiv Observations of Asteroids: Analysis and New Reduction with Tycho-2 and Gaia Catalogs
Shatokhina, S. V.; Kazantseva, L. V.
For more than 50 years, the continuous photographic observations of asteroids have been carried outwith telescopes of the Astronomical Observatory of the Taras Shevchenko National University of Kyiv and the Main Astronomical Observatory of the National Academy of Sciences of Ukraine. About 3,000 photographic plates were obtained, some of which wer…
Asteroid Positions Based on the Dushanbe Part of the FON Project Observations
Andruk, V. M.; Shatokhina, S. V.; Yizhakevych, O. M. +4 more
Asteroid images identification and creation the positional catalogs based on digitized photographic observations of previous years were continued. Namely, the cooperation between Ukrainian Virtual Observatory (UkrVO) and the Institute of Astrophysics of the Academy of Sciences of Tajikistan make it possible to expand this work by involving numerou…
Discrete X-Ray Sources in Galaxy Clusters
Tugay, A. V.; Zadorozhna, L. V.; Shevchenko, S. Yu.
Current studies of extragalactic X-ray sources using data from orbital observatory XMM- Newton are at the front line of X-ray astronomy. Resolution capacity of the observatory instruments enable to detect separate X-ray sources in the close galaxies. In this study we used data from recently published 4XMM-DR9 catalog. This catalog contains 550124 …
Re-Reduction of the Old Photographic Observations of Interamnia (704) Based on Gaia DR2 Reference Catalogue
Protsyuk, Yu. I.; Maigurova, N. V.
A new astrometric reduction of old photographic astroplates benefiting from integration of modern technologies such as the high precision digitizing machines and the high precision Gaia DR2 catalogue could be useful to study the orbital motion of Solar system minor bodies. Based on the newly released Gaia DR2 star catalogue, the scans of the photo…
Software for Search and Measuring of WDS Catalog Double and Multiple Stars from Database of Results of CCD Observation
Protsyuk, Yu. I.; Maigurova, N. V.
Double and multiple star systems are the source of unique information for determining the parameters of star formation models and for testing stellar models evolution. Therefore observations and measuring of their mutual configuration parameters is still important. Observations of double and multiple star systems at the Research Institute "Mykolai…