Lozitsky V.G., Baranovsky E.A., Lozitska N.I., Tarashchuk V.P. «Estimations of local magnetic fields in solar flares: basic methods and some results» Публикации Одесской астрономической обсерватории (Odessa Astronomical Publications, Украина), 30, с. 232-235 (2017)

DOI: https://doi.org/10.18524/1810-4215.2017.30.114690 We consider three methods for estimations of local magnetic fields in solar flares: (1) analysis of bisectors of I±V profiles (Lozitsky, 2015); (2) search for Zeeman-like effects in cores of spectral lines with very low Lande factors, g_eff≈0.01 (Lozitsky, 1993, 1998); (3) semi-empirical modeling using many spectral lines and two-component models (see, e.g., Lozitsky et al., 2000). We illustrate the application of named methods to different observational data and to different spectral lines. Our main conclusions are following: (a) upper limit of local magnetic fields in solar flares is, at least, ∼10⁴G, (b) such extremely strong fields can occur in very small, spatially unresolved scales, (c) lifetime of such fields is, at least, a few minutes.

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.

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.

Parshina S.S., Tokayeva L.K., Dolgova E.M., Afanas'yeva T.N., Samsonov S.N., Petrova V.D., Vodolagina E.S., Kaplanova T.I., Potapova M.V. «Erythrocytes functional features in the 11-year solar cycle» Публикации Одесской астрономической обсерватории (Odessa Astronomical Publications, Украина), 30, с. 240-241 (2017)

DOI: https://doi.org/10.18524/1810-4215.2017.30.114691 There had been studied features of rheological blood failures in patients with unstable angina (UA) in periods of the high (HSA) and low solar activity (LSA) in the 23^rd 11-year solar cycle. This category of patients is characterized by prethrombotic blood state, although they don’t have coronary thrombosis. The research aimed to study compensatory mechanisms which block thrombosis development at the solar activity increase. There had been established that the period of the solar activity increasing in the 11-year solar cycle is characterized by an increase of a blood viscosity, comparing with the period of a low solar activity. Though, erythrocytes functional features in this case are compensatory mechanisms – erythrocyte aggregation paradoxically reduced and their deformability increases. It is probably connected with the revealed fibrinogen decrease in the period of the high solar activity. We can see that the change of a solar activity is accompanied not only by the progressing of pathologic processes, but also by an activation of adaptive changes in erythrocyte membrane so0 as to prevent thrombosis. Though, the required compensatory mechanisms were found invalid, which were shown in the decrease of an oxygen delivery to tissues, and the effectiveness decrease of the medical treatment in the period of a HSA.

Voitko A.S., Troianskyi V.V. «Resonances in Saturn's system» Публикации Одесской астрономической обсерватории (Odessa Astronomical Publications, Украина), 30, с. 250-251 (2017)

DOI: https://doi.org/10.18524/1810-4215.2017.30.117157 One of principal tasks of celestial mechanics is study of motion of natural satellites of planets. In this work, the authors have examined resonances in system of satellites and rings of Saturn. They have showed presence of resonances between all the regular satellites and satellites – rings.

Isaeva E.A., Tsap Yu.T. «Microwave emission of solar flares: coronal mass ejections and shock waves» Публикации Одесской астрономической обсерватории (Odessa Astronomical Publications, Украина), 30, с. 222-225 (2017)

DOI: https://doi.org/10.18524/1810-4215.2017.30.114670 Coronal mass ejections (CMEs) mostly affect the geomagnetic field. These structures are observed and studied with coronagraphic images therefore we don’t see the corona in the plane of the sky and the measurements of the propagation speed for solar disk events are not accessible to coronagraphic observations. This suggests that microwave emission of solar flares that can be attributed to the gyrosynchrotron mechanism of mildly relativistic electrons can be used. In turn, the relationship between coronal shock waves and CMEs also remains unclear. The data set that we use in this study is based on microwave (μ) observations of spectral fluxes F_μ at 8.8 GHz obtained with the Radio Solar Telescope Network for the 124 proton solar events . The correlation coefficient r between the CME velocities V_CME and integral fluxes of microwave emission ∫F_μdt achieves of about 0.8 while it does not exceed 0.36 between V_CME and the shock wave velocities. It has been found the quite strong correlation between the growth rate of microwave emission and the deceleration of frequency drift in the frequency range of 25–180 GHz (r≈0.66). The obtained results suggest that microwave observation can be used to predict V_CME and the shock wave generation occurs in the region of flare energy release.

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.

Pankov A.A., Tsytrinov A.V. «Spin and model determination of extra neutral gauge bosons at LHC and ILC» Публикации Одесской астрономической обсерватории (Odessa Astronomical Publications, Украина), 30, с. 38-40 (2017)

Heavy neutral gauge Z' bosons are predicted by many models of physics beyond the Standard Model. If a new neutral gauge boson is discovered at the LHC in the clean Drell–Yan channel, the characterization of its spin and couplings will proceed via measuring production rates and angular distributions of the decay products. We study the discrimination between a Z' boson (spin-1) against the Randall–Sundrum graviton resonance (spin-2) and spin-0 resonance (sneutrino) with the same mass and producing the same number of events in the cross section. The next step would be to measure its properties to identify the underlying theory that gave rise to the Z'. We discuss in this context the foreseeable sensitivity to Z's of fermion-pair production observables at the ILC with polarized beams, especially as regards the potential of distinguishing different Z' models once such deviations are observed.

Shevchenko S.Yu., Tugay A.V. «Determination of the galaxy cluster orientation using x-ray images by FOCAS method» Публикации Одесской астрономической обсерватории (Odessa Astronomical Publications, Украина), 30, с. 45-47 (2017)

DOI: https://doi.org/10.18524/1810-4215.2017.30.114263 In our work we considered orientations of bright X-ray halos of the galaxy clusters (mainly Abell clusters). 78 appropriate clusters were selected using data from Xgal sample of extragalactic objects in XMM-Newton observation archive. Position angles and eccentricities of these halos were calculated applying FOCAS method. No privileged orientations were found.

Tugay A.V. «Statistical analysis of large-scale structure of Universe» Публикации Одесской астрономической обсерватории (Odessa Astronomical Publications, Украина), 30, с. 51-53 (2017)

While galaxy cluster catalogs were compiled many decades ago, other structural elements of cosmic web are detected at definite level only in the newest works. For example, extragalactic filaments were described by velocity field and SDSS galaxy distribution during the last years. Large-scale structure of the Universe could be also mapped in the future using ATHENA observations in X-rays and SKA in radio band. Until detailed observations are not available for the most volume of Universe, some integral statistical parameters can be used for its description. Such methods as galaxy correlation function, power spectrum, statistical moments and peak statistics are commonly used with this aim. The parameters of powerspectrum and other statistics are important for constraining the models of dark matter, dark energy, inflation and brane cosmology. In the present work we describe the growth of large-scale density fluctuations in one- and three-dimensional case with Fourier harmonics of hydrodynamical parameters. In result we get power-law relation for the matter power spectrum

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.