Odesa Astronomical Publications

Постійне посилання зібрання

https://dspace.onu.edu.ua/handle/123456789/13200

ISSN 1810-4215
eISSN 2786-5215

Журнал «Одеські астрономічні публікації» публікує наукові статі з питань астрономії, астрофізики, космічних досліджень, а також матеріали конференцій, які організовуються й проводяться за участю НДІ «Астрономічна обсерваторія» Одеського національного університету імені І. І. Мечникова.

Повні тексти видання доступні на сайті Наукової бібліотеки ОНУ імені І. І. Мечникова за посиланням:
https://lib.onu.edu.ua/ukrayinska-odessa-astronomical-publications/

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Preparing radio and optical data for comparing binary black hole candidates: the case of OJ 287
(Одеський національний університет імені І. І. Мечникова, 2025) Zabora, Daniil A.; Ryabov, Mykhailo I.; Sukharev, A. L.; Забора, Данііл Андрійович; Рябов, Михайло Іванович; Сухарев, А. Л.
Background. In light of recent discoveries, in particular the appearance in the literature of strong evidence in favor of a binary supermassive black hole (SMBH) in the core of OJ 287, interest in the search for such objects has revived. Therefore, the issue of detecting candidates has gained considerable relevance. The variability of the radio flux of Active Galactic Nuclei (AGN) in the optical, radio and spatial dimensions provides significant insights into the complex structure of physical phenomena in the immediate vicinity of the black hole and the conditions for launching jets. In particular, these manifestations may indicate the presence of a binary SMBH in the center of such a system. Data & methods. The paper uses multi-filter optical observations (aggregated by AAVSO) and radio observations of the MOJAVE project at 15 GHz, given in Lister et al. (2019), in the form of radio fluxes and bright component positions (obtained from the VizieR database). Time-frequency analysis methods (including wavelet analysis, LombScargle, and cross-correlation) as well as clustering and regression methods of machine learning and analysis are used for processing. Results. The intersections of the accretion disk by the companion black hole in the core of OJ 287 cause characteristic optical flares and affect the jet morphology. The latter is manifested in the change in the angles of the bright features (components). It is found that these changes in the case of OJ 287 exhibit noticeable patterns that can be used as indicators for binary black hole candidates (SMBBHs) in active nuclei. Conclusions. The established connection between optical flares (with potential X-ray verification) and changes in the orientation of jet components with a characteristic pattern can serve as a criterion for detecting binary black hole candidates in AGN.
Illumination of artificial Earth satellites in circular orbits
(Одеський національний університет імені І. І. Мечникова, 2025) Strautman, A.; Bazyey, Oleksandr A.; Страутман, А.; Базєй, Олександр Анатолійович
The purpose of the work is to build an updated model of the illumination of artificial satellites in circular Earth orbits and to study the duration and nature of solar illumination in orbits with different inclinations and altitudes throughout the year. The mathematical model uses the equation of the circular cone of the shadow, built taking into account the movement of the Sun relative to the Earth. The center of the cross section of the base of the cone coincides with the center of the Earth. The motion of the satellite is simulated by Kepler’s orbit. The computer model makes it possible to determine with a given accuracy the duration of the satellite’s stay in the Earth’s shadow. Simulation of the duration of illumination of satellites at two altitudes has been performed: 5,000 km and 35,786 km (geosynchronous orbit altitude) throughout the year. Curves of the duration of the satellites’ stay in the shadow are given. The shape of the curves varies from a nearly straight line for inclined orbits 25°, then they become periodic, and then divide into two parts, resembling the shape of a parabola. Among all the possible inclinations of the orbits of satellites, extreme ones have been detected. These are orbits with an angle of inclination 23°26', which defines a straight orbit. On them, an artificial satellite falls into the Earth’s shadow throughout the year at each orbit. The second group of extreme orbits are orbits with inclinations, in which the satellite falls into the shadow only near the time of the equinoxes. Shortest duration of stay of satellites in the shadow moving in orbits with an angle of inclination 113°26'. Falling into the shadow lasts from 15.02 to 23.04 and from 19.08 to 27.10 for an altitude of 5,000 km, and from 12.03 to 28.03 and from 14.09 to 01.10 for an altitude of 35,786 km. The results of the simulations will allow us to clarify the effect of sunlight and solar wind pressure on the motion of satellites over time. This will allow the use of additional satellite accelerations resulting from radiative impact to change the orbits of space debris and clean up near-Earth space.
Evolution of the rotation parameters of the rocket’s upper stage (space object 1987-074G)
(Одеський національний університет імені І. І. Мечникова, 2025) Koshkin, Mykola I.; Kozhukhov, O.; Shakun, Leonid S.; Bryukhovetskyi, O.; Korobeinikova, Olena O.; Melikyants, Seda M.; Strakhova, Svitlana L.; Dragomiretsky, V. V.; Ryabov, A.; Кошкін, Микола Іванович; Кожухов, О.; Шакун, Леонід Сергійович; Брюховецький, О.; Коробейнікова, Олена Олександрівна; Мелікянц, Седа Мнацаканівна; Страхова, Світлана Леонідівна; Драгомірецький, В. В.; Рябов, А.
Active space debris removal operations require a priori knowledge of the target objects’ rotation parameters, i.e., information on their rotation speed and current orientation in space. This can be achieved through appropriate observations designed to determine these parameters. Recording and subsequent analysis of light curves is the most common method for monitoring space objects’ rotation using optical means. This paper examines the results of long-term photometric observations of a large space debris object — the third stage of the SL-14 rocket (international COSPAR number 1987-074G, USSTRATCOM ID 18340). It shows how this resident space object’s (RSO) rotation speed around its center of mass repeatedly changed between 2006 and 2025. To understand the cause of this behavior of RSO 18340, it is necessary to study the relationship between its different rotation speed states and the corresponding orientation of its rotation axis in inertial space. In paper, we consider the observed light curves of RSO 18340, recorded in 2024 at different observatories, analyze their structure and identify similar photometric patterns in different light curves. These photometric patterns are used to determine the spatial direction of the object’s rotation axis in two short (1–3 days) time intervals in late February – early March 2024. As a result of this analysis of the light curves, four estimates of the average direction of the rotation axis and its evolution over a two-week interval were obtained. Using two light curves obtained during flybys over different observing points on February 27, 2024, we obtained the current direction of the rotation axis in the inertial coordinate system: RA = 10°, Decl. = -66°. And based on six light curves obtained on March 9, 10 and 11, 2024, the following average coordinates were determined: RA = 06°, Decl. = -39°. We estimate the internal error of these results to be ±(5–10)°. Based on these results, we hypothesize that there are no rapid shifts in the rotation axis of RSO 18340.
Determining the orbit of the temporary Earth satellite of asteroid 2024 PT5
(Одеський національний університет імені І. І. Мечникова, 2025) Karastan, Mykyta D.; Bazyey, Oleksandr A.; Карастан, Микита Дмитрович; Базєй, Олександр Анатолійович
This study investigates the gravitational inﬂuence of the major planets and the Moon on the orbital dynamics and mechanical energy of near-Earth asteroid 2024 PT5 during its temporary capture by Earth. Discovered on 7 August 2024 by the ATLAS Sutherland survey, the asteroid transitioned onto an elliptical geocentric orbit in late September 2024 and returned to a heliocentric trajectory in mid-November 2024. The primary objective is to determine which massive bodies of the Solar System speciﬁcally the Moon and the nearest planets facilitated the capture process, induced changes in the asteroid’s total mechanical energy during the capture phase, and provided the key perturbations leading to its escape from Earth’s gravitational ﬁeld. High-precision geocentric ephemerides and osculating orbital elements were obtained from the JPL Horizons service. Numerical analyses of the time series for kinetic, potential, and total mechanical energy, as well as eccentricity, were performed to characterize both the capture and release phases. Particular attention was given to the temporal correlations between the asteroid’s close approaches to the Moon and to the major planets, and the corresponding variations in its orbital elements. This approach isolates the intervals during which 2024 PT5 experienced the most pronounced dynamical changes, thereby informing targeted numerical simulations. The methodology includes a detailed statement of the problem and computational procedure, including the criteria used to deﬁne the start and end of the temporary satellite phase and efforts to identify the bodies exerting the strongest gravitational inﬂuence. The results lay the groundwork for developing a general algorithm to assess the probability of capture for any near-Earth object, and to evaluate its potential hazard or scientiﬁc value for future sample-return missions. Application of these techniques promises to enhance the precision of asteroid trajectory forecasts and to support ongoing planetary defense initiatives.
3D image of Polaris field stars
(Одеський національний університет імені І. І. Мечникова, 2025) Usenko, Igor O.; Kaliuzhnyi, M. P.; Miroshnichenko, A. S.; Danford, S.; Turner, D. G.; Majaess, D. J.; Balam, D. D.; Усенко, Ігор Олександрович; Калюжний, М. П.; Мірошніченко, А. С.; Данфорд, С.; Тьорнер, Д.; Маджаєсс, Д. Дж.; Балам, Д. Д.
We present a three-dimensional model of the positions of 20 stars in the field of the Cepheid UMi (Polaris) – 18 main sequence stars (spectral types A0–G0 V), the K-giant HD 6319 (K2 III) and Polaris itself (F8 Ib) – which was created using the 3D calculator Desmos 3D, based on the calculated U, V and W components of the full velocity vector of the stars in the Galactic coordinate system. In this paper, stellar radial velocity estimates from Usenko et al. (2023) were used. Two versions of the U, V, and W components were calculated based on Gaia DR3 parallaxes and photometric parallaxes. The resulting 3D image showed that, in both scenarios, 15 main-sequence stars, a K-giant, and Polaris form a noticeable clamp, while three stars (HD 14718, HD 90162, and HD 11696) are located outside of it. HD 14718 and HD 90162 belong to the thick disk, while HD 11696 is a remnant of a possible open cluster in Polaris’s field. The K-giant HD 6319 is located inside the clamp and quite close to the Cepheid, and it is quite possible that this clamp is part of the main component of the probable open cluster Polaris, dissolved in the field of the Cepheid. Using a 3D calculator to construct a spatial image of stars may serve as a good tool for studying the structure and dynamics of open clusters in the future.
Enrichment with the first- and second-peak s-process elements in Galactic disc giants
(Одеський національний університет імені І. І. Мечникова, 2025) Mishenina, Tamara V.; Gorbanova, Tetiana I.; Pignatari, M.; Kurtukian-Nieto, T.; Мішеніна, Тамара Василівна; Горбаньова, Тетяна Іванівна; Піньятарі, М.; Куртукян-Нєто, Т.
The distribution patterns of chemical elements in the Galactic disc remain insufficiently described. In particular, despite considerable attention to the enrichment of disc stars with neutron-capture elements, several questions remain unresolved and warrant further investigation. In this study, we examine the enrichment of disc stars with first- and second-peak slow neutron-capture (s-process) elements using a sample of 150 Galactic disc giants. Their spectra were obtained with the 1.93-m telescope at the Observatoire de Haute-Provence (France), using the ELODIE echelle spectrograph. Elemental abundances of the first-peak (Sr, Y, Zr) and second-peak (Ba, La, Ce) s-process elements were determined using synthetic spectrum fitting under the assumption of Local Thermodynamic Equilibrium (LTE). The results were compared with predictions from Galactic Chemical Evolution (GCE) models. Our findings confirm that the enrichment in both first- and second-peak s-process elements is driven by contributions from both the s-process and r-process, with a possible additional input from other nucleosynthesis sources.
The features of FI Sge photometric variability on Transiting Exoplanet Survey Satellite observations
(Одеський національний університет імені І. І. Мечникова, 2025) Keir, Leonid E.; Panko, Olena O.; Pyatnytskyy, M. Yu.; Кейр, Леонід Едуардович; Панько, Олена Олексіївна; П’ятницький, М. Ю.
We present the result of the analysis of the FI Sge individual light curves constructed on Transiting Exoplanet Survey Satellite (TESS) observations. FI Sge the RR Lyrae pulsating variable star with bicyclicity effects and possible Blazhko effect. In the present study, we analyzed 3603 photometric data obtained by the Transiting Exoplanet Survey Satellite (TESS) in the special TESS IR bandpass with a time resolution of about 10 minutes. The observations covered a 27-day interval (BJD 2459769.90 − 2459796.12) with a small gap of about a day. The full data set contains 52 minima and 51 maxima of the seasonal light curve. We suppose that for this data set, the analysis of the light curve shapes in minima provides more reliable results. We studied the variations of the minima’ shapes of the individual light curves at common and for the separate affinity groups. The last one allowed us to detect not only classical bicyclicity, but also secondary bicyclicity for FI Sge. This result was obtained at first and it is atypical behavior of light curves for pulsating variable stars.
Unistellar eVscope 2: technical specifications, user community, and prospects for application
(Одеський національний університет імені І. І. Мечникова, 2025) Pechko, Anastasiia K.; Panko, Olena O.; Vasylchenko, V. V.; Mirochnik, N. P.; Печко, Анастасія Костянтинівна; Панько, Олена Олексіївна; Васильченко, В. В.; Мірочнік, Н. П.
The Unistellar eVscope2 represents a new generation of compact astronomical instruments that combine portability, automation, and digital networking to empower both professional and citizen astronomers. This study evaluates the telescope’s technical performance, educational potential, and scientific applications, particularly in exoplanet transit photometry. Based on the comparison of our observational data obtained within the Unistellar global network and professional OGLE data, we showed the great possibility of this approach. Our results demonstrate that high-quality light curves can be produced even under sub-optimal conditions, and compact digital telescopes can play an essential role in expanding observational coverage and in training the next generation of astronomers. The Unistellar network model, combining technological innovation, social participation, and data integrity, stands as a powerful example of how future astronomy will operate at the intersection of professional and citizen science.
Using Cluster Cartography 2D+ for detecting substructures in the 3D Galaxy clusters
(Одеський національний університет імені І. І. Мечникова, 2025) Panko, Olena O.; Yemelianov, S. I.; Lavreniuk, D. O.; Панько, Олена Олексіївна; Ємельянов, С. І.; Лавренюк, Д. О.
In our detailed study of the inner structure of PF galaxy clusters, we found different kinds of substructures in these objects. Most of the detected substructures are quite common. In addition to the classical filamentary features described by Rood and coauthors’ papers, we include complex cross-shaped substructures and short dense chains of galaxies as regular. We suppose that regular substructures are connected with the Large-Scale Structure of the Universe elements, which form the parent cluster node. Our previous studies were based on the list of galaxies of the Muenster Red Sky Survey, which has no redshifts. It allowed us to study only the 2D distribution of galaxies inside the cluster. Modern data, such as the Sloan Digital Sky Survey, the VIMOS Public Extragalactic Redshift Survey, the Euclid Wide Survey, and others, give us the opportunity for 3D studies of these objects. We improved the base online version of the “Cluster Cartography 2D” tool (https://clustercartography.github.io/) into the “Cluster Cartography 2D+” tool. It allows to apply the algorithms developed for 2D version to the detection of regular substructures on a statistically significant level for the 3D distribution of galaxies in the rectangular projections. We tested this opportunity on artificial galaxy clusters with different kinds of substructures. We have shown that using 2D projections allows us to detect the 3D regular substructures, and to restore their real shapes and directions.
Onomastics and Names of the Starry Sky. To the 95th anniversary of Professor, Corresponding Member of the Academy of Sciences of Ukraine Yu. O. Karpenko – the author of the book "Names of the Starry Sky"
(Odesa I. I. Mechnikov National University, 2024) Karpenko, Olena Yu.; Ryabov, Mykhailo I.; Карпенко, Олена Юріївна; Рябов, Михайло Іванович
In 2024, the 95th anniversary of the outstanding scientist, encyclopedist, Professor Yuriy Olexandrovich Karpenko is celebrated. Yu. O. Karpenko taught for many years at the Faculty of Philology Odesa Mechnikov National University. Yuriy Olexandrovich Karpenko, being a philologist, expanded the object of his research to include the entire Universe. The results of his research are reflected in the book "Names of the Starry Sky", which is still unique today. In the words of Yu. O. Karpenko himself: "The human path of knowledge has always been accompanied by words. Man denoted all his discoveries and victories by means of language – he named them. Without this, without such names, there would be no point in thinking about the accumulation of knowledge, about passing it on to subsequent generations." The authors of the report hope that the life of the wonderful book by Yu. O. Karpenko "Names of the Starry Sky" will be continued by its translation into English and Ukrainian.
Astrometry of NASA Lucy mission targets (617) Patroclus, (3548) Eurybates, and (21900) Orus at opposition 2021
(Odesa I. I. Mechnikov National University, 2024) Troianskyi, Volodymyr V.; Okhotko, Hanna K.; Kashuba, Volodymyr I.; Udovichenko, Serhii M.; Keir, Leonid E.; Romanyuk, Ya.; Savanevych, V.; Khlamov, S.; Briukhovetskyi, A.; Zhukov, V.; Lishchynskyi, I.; Poplavskyi, O.; Trunova, T.; Троянський, Володимир Володимирович; Охотко, Ганна Костянтинівна; Кашуба, Володимир Іванович; Удовіченко, Сергій Миколайович; Кейр, Леонід Едуардович; Романюк, Я.; Саваневич, В.; Хламов, С.; Брюховецький, О.; Жуков, В.; Ліщинський, І.; Поплавський, О.; Трунова, Т.
In this paper we present the result of the combined use of the OMT-800, AZT-3, KIT telescopes, and the Lemur software of the CoLiTec project. The paper considers in detail several of the astrometric observations of Jupiter Trojan asteroids: (617) Patroclus, (3548) Eurybates, and (21900) Orus from a long list of small bodies of the Solar System.
Using synthetic light curves of artificial satellite model to test the patterns method for determining the rotation axis orientation
(Odesa I. I. Mechnikov National University, 2024) Koshkin, Mykola I.; Shakun, Leonid S.; Korobeinikova, Olena O.; Melikyants, Seda M.; Strakhova, Svitlana L.; Kozhukhov, O. M.; Кошкін, Микола Іванович; Шакун, Леонід Сергійович; Коробейнікова, Олена Олександрівна; Мелікянц, Седа Мнацаканівна; Страхова, Світлана Леонідівна; Кожухов, О. М.
In this paper we test a new method for determining the rotation axis direction in space for various resident space objects (RSOs). This method (Koshkin et al., 2024) is based on the structural analysis of the light curves of such RSOs and the search for similar fragments, called "photometric patterns", in observations obtained from one or several observatories simultaneously or over a short period of time. The method does not require prior knowledge of the RSO shape and does not impose strict requirements on the quality of observations, and this is its main advantage. First of all, this method is certainly applicable to rapidly rotating objects of complex shape with smooth surfaces. As a result, such RSOs are capable to reflect sunlight in a specular manner, when short-term brightness flares are present in the light curves forming a unique pattern. Identical patterns are observed when the angle between the phase angle bisector (PAB) and the rotation axis reaches the same values. However, the light curves of many RSOs have a significant diffuse component in addition to the specular flares. This diffuse component depends on both the phase angle value and the orientation of the phase angle plane relative to the RSO’s plane of rotation. This paper is devoted to checking the assumption that the structure and shape of diffuse-specular patterns will remain similar to themselves within certain limits of variation of the value of these two angles at moments of equality of the PABs’ latitude. The analysis is based on simulation using synthetic light curves of the RSO model, observed from several points on the Earth's surface.
Investigation of the radioactive promethium lines in stellar spectra
(Odesa I. I. Mechnikov National University, 2024) Yushchenko, Volodymyr O.; Gopka, Vira F.; Yushchenko, A. V.; Pavlenko, Ya V.; Shavrina, A. V.; Demessinova, A.; Vasilieva, S. V.; Ющенко, Володимир Олександрович; Гопка, Віра Федорівна; Ющенко, О. В.; Павленко, Я. В.; Шавріна, А. В.; Демесінова, А.; Васильєва, С. В.
Eleven lines of promethium Pm II in the spectra of the magnetic peculiar A0 V star HD 25354 were analysed thoroughly in order to obtain information about how the short-lived element lines behave in spectra acquired on different observation dates. It has turned out that the intensity variations in time are typical for these lines with some of them being observed as emissive or absent at certain time intervals. The obtained list of Pm II lines in the spectra of the magnetic peculiar star HD 25354 has been employed to investigate promethium abundances in atmospheres of other stars, such as HR 465 (Teff = 111,840 K), HIP 13962 (Teff = 6,250 K) and BL 138 (Teff = 3,939 K). The investigation interval has been limited to the spectral range of 4000–5800 Å and oscillator strengths within –0.76 < log gf < 0.4.
Spectroscopic studies of Polaris: getting back to normal life of a Cepheid?
(Odesa I. I. Mechnikov National University, 2024) Usenko, Igor O.; Miroshnichenko, A. S.; Danford, S.; Vaidman, N. L.; Turner, D. G.; Majaess, D. J.; Protsyuk, S. V.; Усенко, Ігор Олександрович; Мірошніченко, А. С.; Данфорд, С.; Вайдман, Н. Л.; Тьорнер, Д.; Маджаєсс, Д. Дж.; Процюк, С. В.
Based on 583 radial velocity (RV) measurements we obtained at the Three College Observatory (TCO, North Carolina, USA) in 2015–2024, (including 396 not previously analyzed from 2020–2024) as well as on 236 RV data from the German amateur R. Bücke (2011–2022), we calculated the pulsation period and amplitude of the Cepheid Polaris Aa system (α UMi). The analysis showed that the pulsation period was stable within a few minutes in 2020–2024. During this time, the pulsation amplitude was increasing and reached the 1960s level (4–6 km s−1), when its sharp decline began. Since its new growth began after Polaris Ab, the system secondary component, passed a periastron, we concluded that the observed amplitude changes were due to its orbital motion. It is clear that Polaris Aa is returning to normal pulsating activity.
Specific features of the enrichment of metal-poor stars with neutron-capture (r-process) elements
(Odesa I. I. Mechnikov National University, 2024) Mishenina, Tamara V.; Gorbanova, Tetiana I.; Dmytrenko, A.; Pignatari, M.; Thielemann, F.-K.; Мішеніна, Тамара Василівна; Горбаньова, Тетяна Іванівна; Дмитренко, А.; Піньятарі, М.; Тілеманн, Ф.-К.
In contrast to stars with near-solar metallicity (Galactic disk stars), metal-deficient stars show an abundance scatter of up to 3 dex in the enrichment with neutron-capture elements, in particular the r-process elements. The reasons of such a large variation in the in the r-process nucleosynthesis is currently matter of debate. Possible scenarios could be the presence of various r-process stellar and mechanisms in the early unevenly mixed Galaxy, as well as different stellar origin, either galactic or extragalactic, that reflect entering the Galaxy after the capture or coalescence of both individual stars and more complex stellar associations and star formations. In order to study differences in the enrichment with the r-process elements, we selected 20 metal-deficient stars, the spectra of which were collected in the UVES/VLT archive. We employed earlier determined atmospheric parameters to calculate the abundances of about 20 neutron-capture elements via the synthetic spectrum method, taking into account the hyperfine structure for a number of elements. We performed an analysis of the enrichment with the r-process elements grounded on multiple levels of enrichment intensity – namely, limited r-process, r-I and r-II – and the arrangement of stars by their belonging to different populations of the Galaxy, based on the stars’ spatial velocity components.
The R-band observations and comparison with results in the V-band of FI Sge
(Odesa I. I. Mechnikov National University, 2024) Keir, Leonid E.; Udovichenko, Serhii M.; Кейр, Леонід Едуардович; Удовіченко, Сергій Миколайович
We present the result of the processing of our observations of the FI Sge, the pulsating RR Lyrae type variable with the Blazhko effect in the R-band. The data were obtained during 36 nights in 2018 as well as during 13 nights in 2021. We used the period and initial epoch obtained from our observations in V-band. We confirmed the presence of the Blazhko effect, the bi-cyclicity effect, and also the effect of discrete displacement of the light curves along the phase curve detected firstly in the V-band. We detect some differences in the dynamic of the light curve variability in different photometrical bands, possibly related to the Blazhko effect.
The inner structure of galaxy clusters in the triplets
(Odesa I. I. Mechnikov National University, 2024) Panko, Olena O.; Yemelianov, Sviatoslav I.; Панько, Олена Олексіївна; Ємельянов, Святослав Ігорович
The inner structure of galaxy clusters is determined by the interaction of baryon matter with the surrounding structures and the influence of the underlying dark matter. For the search of the results of such interaction, we select the 18 triplets (11 elongated and 7 rounded ones) of galaxy clusters from the triplets founded in the PF Catalogue of Galaxy Clusters and Groups (Panko & Flin). The shape of the all founded triplets vary from practically regular triangle to straight chain, i.e., the ellipticity of the best-fitted ellipse of the triplets ranged from 0.12 to 0.92. We select the triplets with ellipticities in the range 0.8−1.0 as the first subset and with the ellipticities in the range 0.1−0.4 as the second one. The comparison the results obtained for two subsets allowed to conclude the elongated triplets arise along the filament. Binggeli effect was detected in a major part of clusters. In the linear substructure L11 in PF 0369–7499 galaxies show also perpendicular alignment in contrast to other galaxies of this cluster. We suppose the substructures in the galaxy clusters of our data set must be connected with the influence of other triplet members.
Motions of the components of AGNS according to VLBI MOJAVE data as indicators of the activity and spatial structure of the jet
(Одеський національний університет імені І. І. Мечникова, 2023) Zabora, Daniil A.; Ryabov, Mykhailo I. ; Sukharev, A.; Bezrukovs, V.; Bazyey, Oleksandr A.; Забора, Данііл Андрійович; Базєй, Олександр Анатолійович; Рябов, Михайло Іванович
The system of ten radio telescopes VLBA (Very Large Baseline Array), with a maximum baseline of about 8,600 km, of the National Radio Astronomy Observatory of the USA (NRAO USA) carries out systematic monitoring observations of about 500 active galactic nuclei (AGN), the results are presented in the MOJAVE database. The resulting angular resolution (~0.47 arcseconds at a frequency of 15.4 GHz) is enough to separate the close surroundings of the AGN and its jet. The results of corresponding observations make it possible to compare the features of movement in the jet with the processes of activity of the AGN, as well as to study its spatial structure. The MOJAVE database contains the spectral densities of the radio fluxes of the AGN, radio images for each epoch of observations at the frequency of 15.4 GHz, and "Separation jet" diagrams (showing the angular separation of the jet components over time). This information makes it possible to study the movement of these components. In this work, a general analysis of movement patterns of the components of the 3C 273 jet was performed. In the published papers of the MOJAVE team, a similar analysis wasn’t presented for all jet’s features.
First reported observation of asteroids 2017 SV39, 2017 ST39, and 2017 TS7
(Одеський національний університет імені І. І. Мечникова, 2023) Simon, A.; Troianskyi, V. V.
In this paper, we show the result of the joint use of the AZT-8 telescope, the Astrometrica software, and the Väisälä method. The paper considers in detail several of the discovered (rediscovered) asteroids: SV39, 2017 ST39, and 2017 TS7 from a long list of small bodies of the Solar System.
Spectroscopic investigations of Polaris field stars
(Одеський національний університет імені І. І. Мечникова, 2023) Usenko, I. A.; Miroshnichenko, A. S.; Danford, S.; Turner, D. G.; Majaess, D. J.; Balam, D. D.
We present the results of an analysis of 28 spectra of 18 Polaris ﬁeld A–G V stars obtained in 2016–2023. Derived radial velocities and Teﬀ along with distances and reddenings from the Gaia DR3 catalog allowed us to calculate radii of the stars and compare them with calibration relationships “Specral type – Luminosity” for MS stars. As a result, radii and distances for 9 stars were found overestimated compred to those determined photometrically. Therefore, the DR3 distances are unreliable and should be revisited. Accordring to our data for these stars and their photometric distances, 15 objects belong to a possible old open cluster that is currently dissolved in the Polarisﬁeldatadistance∼70–110pc, whiletwoobjectsbelong to the thick disk, and one belongs to a possible another star group located at a distance of 130 pc.

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