Oknyansky V.L., Gaskell C.M., Huseynov N.A., Mikailov Kh.M., Lipunov V.M., Malanchev N.I., Tsygankov S.S., Gorbovskov E.S., Tatarnikov A.M., Metlov V.G., Shatsky K.L., Brotherton M.B., Kasper D., Du P., Chen X., Burlak M.A., Buckley D.A.H., Rebolo R., Serra-Ricart M., Podesta R., Levato H. «Ulti-wavelength monitoring of the changing-look AGN NGC 2617 during state changes» Публикации Одесской астрономической обсерватории (Odessa Astronomical Publications, Украина), 30, с. 117-120 (2017)

DOI: https://doi.org/10.18524/1810-4215.2017.30.114366 Optical and near-infrared photometry, optical spectroscopy, and soft X-ray and UV monitoring of the changing-look active galactic nucleus NGC 2617 show that it continues to have the appearance of a type-1 Seyfert galaxy. An optical light curve for 2010–2017 indicates that the change of type probably occurred between 2010 October and 2012 February and was not related to the brightening in 2013. In 2016 and 2017 NGC 2617 brightened again to a level of activity close to that in 2013 April. However, in 2017 from the end of the March to end of July 2017 it was in very low level and starting to change back to a Seyfert 1.8. We find variations in all passbands and in both the intensities and profiles of the broad Balmer lines. A new displaced emission peak has appeared in H_β. X-ray variations are well correlated with UV–optical variability and possibly lead by ∼2–3^d. The K band lags the J band by about 21.5±2.5^d and lags the combined B+J bands by ∼25^d. J lags B by about 3 d. This could be because J-band variability arises predominantly from the outer part of the accretion disc, while K-band variability is dominated by thermal re-emission by dust. We propose that spectral-type changes are a result of increasing central luminosity causing sublimation of the innermost dust in the hollow bi-conical outflow. We briefly discuss various other possible reasons that might explain the dramatic changes in NGC 2617.

Andruk V., Yuldoshev Q., Eglitis I., Pakuliak L., Mullo-Abdolov A., Vaviliva I., Protsyuk Yu., Relke H., Golovnia V., Shatokhina S., Yizhakevych O., Ehgamberdiev Sh., Muminov M., Kokhirova G., Kazantseva L. «On the concept of the enhanced FON catalog compilation» Публикации Одесской астрономической обсерватории (Odessa Astronomical Publications, Украина), 30, с. 159-162 (2017)

Mullo-Abdolov A., Kokhirova G., Relke H., Yuldoshev Q., Protsyuk Yu., Andruk V. «Investigation of the Microtek ScanMaker 1000XL PLUS scanner of the Institute of astrophysics of the Academy of Sciences of the Republic of Tajikistan» Публикации Одесской астрономической обсерватории (Odessa Astronomical Publications, Украина), 30, с. 186-189 (2017)

DOI: https://doi.org/10.18524/1810-4215.2017.30.114407 This work was done to estimate the accuracy of the processing method of photographic plates and the detailed study of the Microtek ScanMaker 1000XL Plus scanner, which plans to be used for the digitizing of about 1600 photographic plates of the Astrophysics Institute of the Academy of Sciences of the Republic of Tajikistan (Dushanbe) recorded for the FON project. For the processing of these photographic plates will be used software created in the LINUX/MIDAS/ROMAFOT environment. Six sequential scans of a single plate (1150, the Pleiades cluster) with a spatial resolution of 1200 dpi were processed to evaluate the repeatability of the scanner's astrometric and photometric errors. The size of photographic plates is 8×8 degrees (30×30 cm or 13000×13000 pixels). The estimated errors of the scanner for the stars brighter than B<13.5^m are σ_xy=±0.054 pixels for the rectangular coordinates and σ_m=±0.020^m for the instrumental magnitudes. The estimated astrometric accuracy of the processing of stellar fields of photographic plates in the system of the Tycho-2 catalogue is σ_αδ=±0.13".

Yuldoshev Q.H., Muminov M.M., Ehgamberdiev Sh.A., Relke H., Protsyuk Yu.I., Kovylianska O.E., Protsyuk S.V., Andruk V.M. «Catalogue of coordinates and B-magnitudes in –20° – +2° zone based on the Ulugh Beg Astronomical institute part of the FON project» Публикации Одесской астрономической обсерватории (Odessa Astronomical Publications, Украина), 30, с. 205-208 (2017)

DOI: https://doi.org/10.18524/1810-4215.2017.30.114443 Catalogue of 13.4 million stars down to 17.5m was obtained in 2017 by using plates from the Kitab Observatory of Ulugh Beg Astronomical Institute (UBAI) of the Uzbek Academy of Sciences. Kitab's part of Photographic Sky Survey (Russian abbreviation is FON, in next contexts) project include more than 2600 photographic plates, exposed on the Double Astrograph of Zeiss (DAZ, D/F=40/300, 69"/mm) from 1981 to 1996. Digitizationof these plates was made by using Epson Expression 10000XL scanner with the 1200 dpi resolution. Catalogue includes objects from the 1963 plates in declination zone between –20° and +2° for middle epoch 1984.97. The equatorial coordinates of objects were determined in the Tycho-2 reference system and the B-magnitudes in the system of the photoelectric standards. Five participants from Uzbekistan, Germany and Ukraine have taken part in the processing of the digitized images. The average internal accuracy of the catalogue for one observation are 0.23" and 0.15^m for the equatorial coordinates and B-magnitudes respectively. For the stars brighter than 14^m the errors are 0.09" and 0.05^m respectively. The analysis of the catalogue and its comparison with the several astrometric catalogues was done.

Rudakovskyi A.V. «Cores in dark matter haloes with anisotropic Osipkov–Merritt distribution and maximal phase-space density» Публикации Одесской астрономической обсерватории (Odessa Astronomical Publications, Украина), 30, с. 41-44 (2017)

DOI: https://doi.org/10.18524/1810-4215.2017.30.114259 This paper describes the developed model of dark matter cored density profiles. This model was recently proposed by Dmytro Iakubovskyi (Iakubovskyi and Rudakovskyi, in preparation). It has only one extra parameter – the maximal value fmax of phase-space distribution function – that turn a cusped Navarro–Frenk–White density profie into a cored one. This paper focuses on the estimation of the influence of velocity anisotropy on the cored density profile by using the Osipkov–Merritt model. The density profiles of the typical dwarf-spheroidal galaxy for different masses of fermionic dark matter particle and different anisotropy parameters r_a was calculated. It was obtained that the influence of velocity anisotropy on the cored density profile is small.

Shakun L., Koshkin N., Korobeynikova E., Strakhova S., Dragomiretsky V., Ryabov A., Melikyants S., Golubovskaya T., Terpan S. «Accuracy of satellite optical observations and precise orbit determination» Публикации Одесской астрономической обсерватории (Odessa Astronomical Publications, Украина), 30, с. 242-245 (2017)

DOI: https://doi.org/10.18524/1810-4215.2017.30.117660 The monitoring of low-orbit space objects (LEO-objects) is performed in the Astronomical Observatory of Odessa I.I. Mechnikov National University (Ukraine) for many years. Decades-long arсhives of these observations are accessible within Ukrainian network of optical observers (UMOS). In this work, we give an example of orbit determination for the satellite with the 1500-km height of orbit based on angular observations in our observatory (Int. No. 086). For estimation of the measurement accuracy and accuracy of determination and propagation of satellite position, we analyze the observations of Ajisai satellite with the well-determined orbit. This allows making justified conclusions not only about random errors of separate measurements, but also to analyze the presence of systematic errors, including external ones to the measurement process. We have shown that the accuracy of one measurement has the standard deviation about 1 arcsec across the track and 1.4 arcsec along the track and systematical shifts in measurements of one track do not exceed 0.45 arcsec. Ajisai position in the interval of the orbit fitting is predicted with accuracy better than 30 m along the orbit and better than 10 m across the orbit for any its point.