Maharramov Y.M. «H_α and H_β profile variations in the spectra of the star 55 Cyg» Публикации Одесской астрономической обсерватории (Odessa Astronomical Publications, Украина), 30, с. 101-107 (2017)

DOI: https://doi.org/10.18524/1810-4215.2017.30.114351 We study the variability of the H_α and H_β lines in the spectra of 55 Cyg based on observations acquired in 2014 on the 2-m telescope of Shamakhy Astrophysical Observatory. In this work line profiles of H_α and H_β are described extensively and compared with early observations. The profile of H_α line vanishes or almost vanishes in the spectra on some epochs again. Our observations showed that when the H_α line disappeared or weaken sharply in the spectra, the HeI and H_β line are redshifted, but no synchronous variabilities were observed in other spectral lines (CII and others) formed in deeper layers of the stellar atmosphere. In addition, the profiles of the H_α and H_β lines have been analysed, as well as their relations with possible conditions of the atmosphere of 55 Cyg. We revealed that the structures of photospheric (CII, HeI etc.) absorption line profiles, as well as H_β line, their radial velocities and equivalent widths are variable. These events may be associated with a manifestation of the non-stationarity of the atmosphere or non-sphericity of the stellar wind.

Maigurova N.V., Pomazan A.V., Bodryagin D.V., Bondarchuk L.E. «Accuracy of Mykolaiv asteroid observations with different reference catalogues» Публикации Одесской астрономической обсерватории (Odessa Astronomical Publications, Украина), 30, с. 182-185 (2017)

DOI: https://doi.org/10.18524/1810-4215.2017.30.114488 The results of astrometric reductions of main belt asteroid observations with usage of 3 different reference catalogues are presented. The high precision catalogs CMC15, UCAC4 and GAIA DR1 were used as reference catalogues for calculation asteroid equatorial coordinates. The asteroid observations were carried out at KT-50 telescope of the RI “MAO” Mobitel complex during 2016. The array contains 1666.positions of 68 asteroids mainly in range of (11–15) magnitudes. The differences (O–C) were calculated by comparing the obtained topocentric positions with the HORIZONS ephemeredes of the JPL laboratory. The mean square errors of the (O–C) values were used for comparison of the different reductions model. The influence of the choice of the reference catalog on the random and systematic asteroid position errors is shown.

Pomazan A.V., Maigurova N.V., Shulga O.V. «The astrometric results of observations of periodical comets at KT-50 telescope in RI “MAO”» Публикации Одесской астрономической обсерватории (Odessa Astronomical Publications, Украина), 30, с. 190-193 (2017)

DOI: https://doi.org/10.18524/1810-4215.2017.30.114490 The astrometric results of the observations of 10 periodical comets in 2017 are presented. The observations were made with telescope KT-50 telescope in RI «Mykolaiv Astronomical Observatory». The differences between the measured from observations (O) and calculated from ephemeris (C) positions and their mean square errors (MSE) were calculated. The ephemeris positions were taken from online computation service HORIZONS (JPL NASA, USA). For the measured positions the average MSE values are 0.17" in right ascension and 0.18" in declination respectively. Analysis of the values (О–C) before and after additions of obtained positions to Minor Planet Center (MPC) database revealed a gradual decrease of these differences with respect to the ephemeris. This indicates that the using of the new high-precision positions allows us to refine the calculated ephemeris. As well improvement and lengthening of the astrometric datasets play important role in the modeling of the cometary nongravitational effects.

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.

Savastru S.V., Marsakova V.I., Andrych K.D., Dubovsky P. «Improved ephemeris of poorly studied eclipsing binary GSC 3950-00707 = 2mass J20355082+5242136» Публикации Одесской астрономической обсерватории (Odessa Astronomical Publications, Украина), 30, с. 126-127 (2017)

DOI: https://doi.org/10.18524/1810-4215.2017.30.115819 We made our CCD-observations of GSC 3950-00707 by using the telescope Celestron-14 of Vihorlat Observatory and Astronomical Observatory on Kolonica Saddle. The moments of minima were calculated by using the symmetrical polynomial fit. We also analyzed the observations from automated surveys ASAS-SN and found 3 mean minima by using trigonometrical polynomial fit. The analysis of our observations and data from the surveys allows to conclude that it is the W UMa-type variable and its published period value is not accurate. We analyzed the O–C curve and corrected the elements.

Tvardovskyi D.E., Marsakova V.I., Andronov I.L. «Effects of the mass transfer and presence of the third components in close binary stellar systems» Публикации Одесской астрономической обсерватории (Odessa Astronomical Publications, Украина), 30, с. 135-139 (2017)

DOI: https://doi.org/10.18524/1810-4215.2017.30.115463 n our research, we have studied 6 close binary stellar systems which are eclipsing variables of β Lyrae and W Ursae Majoris types of variability. We have studied their O–C curves. To build them, we used moments of minima, listed in the BRNO database. Also, we used ones, which we obtained as the result of processing of observational data taken from AAVSO database. As the result of the O–C analysis, we detected that all of these stars have parabolic O–C curves, which might be caused by mass transfer from one component to another. In an addition, 3 from researched stars (U Peg,V0523 Cas and WZ Cyg) have superimposed parabolic and cyclic O–C changes that could be caused by presence of the third components in the systems. Also, we calculated minimal possible masses of third components, rates of the mass transfer for these systems and corrected the ephemerides.

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.

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.

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.

Miroshnichenko A.P. «Evolution features of giant sources with linear and break steep radio spectra» Публикации Одесской астрономической обсерватории (Odessa Astronomical Publications, Украина), 30, с. 236-239 (2017)

DOI: https://doi.org/10.18524/1810-4215.2017.30.114640 In the framework of the cosmological model ΛM the features of properties of giant radio sources with steep low-frequency spectra of linear (S) and break (C+) types are examined. Our estimates of characteristic age of galaxies and quasars with steep spectrum from the UTR-2 catalogue have values 10⁷–10⁸ years. We consider that steep radio spectra may be formed at the transient injection by synchrotron losses of relativistic electrons. Earlier we have determined two evolution branches in relation of the characteristic age and ratio of emission of torus and accretion disk crown for sources with steep spectra S and C+. To further examination of evolution features of giant sources with steep spectra we consider ratio of emission of radio lobes and accretion disk (and disk crown) versus velocity of jet propagation and characteristic age of these objects. Analysis of obtained relations testifies to periodical activity of giant low frequency steep spectrum radio sources.

Kuratova A.K., Zakhozhay O.V., Kuratov K.S., Zakhozhay V.A., Miroshnichenko A.S. «Physical parameters of protoplanetary disk surrounding IRAS 22150+6109 young star» Публикации Одесской астрономической обсерватории (Odessa Astronomical Publications, Украина), 30, с. 98-100 (2017)

DOI: https://doi.org/10.18524/1810-4215.2017.30.114371

Usenko I.A., Kovtyukh V.V., Miroshnichenko A.S., Danford S. «Pulsational activity of the small-amplitude Cepheid Polaris (α UMi) in 2016–2017» Публикации Одесской астрономической обсерватории (Odessa Astronomical Publications, Украина), 30, с. 146-148 (2017)

DOI: https://doi.org/10.18524/1810-4215.2017.30.114382 We present the results of an analysis of 49 spectra of α UMi (Polaris) obtained during August–December 2016 and January–March 2017. Frequency analysis displays an unexpected decrease of the pulsational period up to 17.3min in comparison to the 2015 observational set. The radial velocity amplitude was reduced to 3.43 km s^–1 in 2016 and to 3.31km s^–1 in the beginning of 2017 in comparison with 4.16 km s^–1 in 2015. This result is also unexpected, because during the last decade a gradual amplitude growth has been observed. The average T_eff=6021 K determined from the 2016–2017 data is close to the values determined for the 2001–2015 set.

Mishenina T., Klochkova V., Panchuk V., Basak N., Kovtyukh V., Korotin S., Velichko A. «Three giants – members of the open cluster M 67» Публикации Одесской астрономической обсерватории (Odessa Astronomical Publications, Украина), 30, с. 108-112 (2017)

DOI: https://doi.org/10.18524/1810-4215.2017.30.114355 We determined the atmospheric parameters and chemical composition of the three giants, which are members of the open cluster M 67. The high resolution spectra (R=60 000) were obtained with the echelle spectrograph NES mounted on the 6-metertelescope of the SAO RAS Obtained variations in Na and Zr abundances are within the determination errors. The Li abundance suggest a depletion of Li in the course ofstellar evolution. For studied giants, the iron abundances derived from the neutral and ionized iron lines have not shown any significant discrepancies. The [Ba/Fe] values are close to the solar ones.

Gorbaneva T.I., Mishenina T.V. «Molybdenum and ruthenium abundances in cool stars of the galactic disc» Публикации Одесской астрономической обсерватории (Odessa Astronomical Publications, Украина), 30, с. 76-77 (2017)

DOI: https://doi.org/10.18524/1810-4215.2017.30.114274 We revise the molybdenum and ruthenium abundances in FGK stars with metallicities ranging from –1.0 < [Fe/H] < +0.3. The observed stars belong to the substructures of the Galaxy. The observations were conducted using the 1.93 m telescope at Observatoire de Haute–Provence (OHP, France) equipped with the echelle type spectrographs ELODIE and SOPHIE. The results are based on analyses of spectra that have a typical S/N ∼100–300 and a resolution of 42 000. These estimates were obtained using synthetic spectra computed with LTE model atmosphere.

Kondratyev V.N., Nurtayeva U.M., Zhomartova A.Zh., Mishenina T.V. «Synthesis of magnetized nuclei at supernova explosion» Публикации Одесской астрономической обсерватории (Odessa Astronomical Publications, Украина), 30, с. 91-92 (2017)

DOI: https://doi.org/10.18524/1810-4215.2017.30.114335 Influence of magnetorotational instabilities in astrophysical plasma at supernova explosion on synthesis of chemical elements is investigated. At field strength less than 10 teratesla nuclear magnetic susceptibility exhibits linear regime with enhanced nuclear binding energy for open shell nuclei. Effects of ultra-strong nuclear magnetization are demonstrated to enhance the portion of titanium product. The relation to an excess of titanium isotopes revealed from the Integral mission data and galactic chemical evolution is discussed.

Koshkin N.I., Savanevich V., Pohorelov A., Shakun L., Zhukov V., Korobeynikova E., Strakhova S., Moskalenko S., Kashuba V., Krasnoshchokov A. «Ukrainian database and atlas of light curves of artificial space objects» Публикации Одесской астрономической обсерватории (Odessa Astronomical Publications, Украина), 30, с. 226-229 (2017)

DOI: https://doi.org/10.18524/1810-4215.2017.30.117655 This paper describes the Ukrainian database of long-term photometric observations of resident space objects (RSO). For the purpose of using this database for the outer space monitoring and space situational awareness (SSA) the open internet resource has been developed. The paper shows examples of using the Atlas of light curves of RSO's for analyzing the state of rotation around the center of mass of several active and non-functioning satellites in orbit.

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".

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)

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.