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/

Сайт видання: http://oap.onu.edu.ua/

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Зараз показуємо 1 - 20 з 225

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, D.; Ryabov, M.; Sukharev, A.; Bezrukovs, V.; Bazyey, Oleksandr A.; Базєй, Олександр Анатолійович
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.
Manifestation of stellar evolution in metal-deficient stars
(Одеський національний університет імені І. І. Мечникова, 2023) Mishenina, Tamara V.; Usenko, I. A.; Kniazev, A. Yu.; Gorbaneva, T. N.; Мішеніна, Тамара Василівна
Metal-poor stars allow us to establish the early history of the Milky Way, furthermore the stars on advanced evolution stage (e.g. giants, AGB stars etc.) give the opportunity to research the peculiarities of stellar evolution at low metallicity. On the base of the 11m Southern African Large Telescope (SALT) spectra obtained using HRS fibre-fed echelle-spectrograph during 2018 -2020, the atmospheric parameters and elemental abundances of four metal-poor stars HE 1523-0901, HD 6268, HD 121135, and HD 195636 ( [Fe/H] ~ -1.5 – -3.0) have been obtained. The iron abundance was determined based on the equivalent widths of absorption lines. The carbon abundance was obtained using the molecular synthesis fitting for the CH (4300-4330 ÅÅ) region, nitrogen from CN at 3883 Å, oxygen from [O] line at 6300 Å and IR triplet at 7770 Å The relationship between the chemical enrichment of stars and their stellar evolution is considered. It may be associated with the processes of mixing inside the stars, and the mechanisms of matter transfer during stellar evolution.
New galactic lithium-rich classical Cepheid: OGLE GD-CEP-0516
(Одеський національний університет імені І. І. Мечникова, 2023) Kovtyukh, Valery V.; Ковтюх, Валерій В.
We report the discovery new superlithium rich beat Cepheid OGLE GD-CEP-0516 which has a lithium abundance of logA(Li)≈3.6 dex. It is the sixth known Cepheid of such type in the Galaxy. OGLE GD-CEP-0516 can be considered as the Cepheid which is presently crossing the instability strip for the ﬁrst time.
A new approach to the analysis of light curves of pulsating RR Lyrae stars with the Blazhko effect
(Одеський національний університет імені І. І. Мечникова, 2023) Keir, Leonid E.; Кейр, Леонід Е.
We discuss the new approach for the analysis of the long-term dense series of observations of RR Lyr-type pulsating stars with the Blazhko eﬀect. The standard way, namely The frequency analysis of the O–C values for the times of maxima does not allow for to detection of the complex nature of the periodic changes in the shape of the light curves, including bi-cyclicity. We have shown the perspectives of a new approach on the example of the analysis of FISge variable observations containing a total of 55 observational nights during a period of ﬁve years (AZT-3 Telescope, Mayaki Observational Station, SRI “Astronomical Observatory”, I.I. Mechnikov ONU). ThestudyisbasedonthedataobtainedbyS.N.Udovichenko during the 2013 and 2014 observational seasons as well as on data obtained by S.N. Udovichenko and the author during the 2018 observational season. Our results show that in order to understand the features in the shape of the light curve variations for RR Lyr type pulsating stars with the Blazhko eﬀect, it is necessary to have data for full cycles of variability over a long time, and not just the moments of maxima.
Galaxy Cluster Mergers: the use of the computer modeling
(Одеський національний університет імені І. І. Мечникова, 2023) Berkovskyi, M.; Panko, Olena O.; Miroshnik, N.; Панько, Олена Олексіївна
We show the possibilities of the methods of computer modeling of the galaxy cluster merger process with diﬀerent initial parameters for the investigation of the features of the clusters after colliding. Weconsideredthegalaxyclustersasevolvingobjects including through collisions. Computer modeling of galaxy cluster mergers and comparing its results with observational data makes it possible to determine the evolutionary status of real clusters with complex internal structures. Within the study, we analyzed in detail a series of models of the galaxy clusters’ merger consequences by ZuHone under diﬀerent initial conditions like mass ratio, initial collision parameter, or plasma coeﬃcient β. The considered time intervals were from 0 to 4.8 billion years, from 0 to 6 billion years, and from 0 to 10 billion years, depending on the initial conditions. Basedontheimagesofthesimulatedgalaxyclusters, maps of the distribution of the total mass density and X-ray radiation were created and compared with observations. We showed a good perspective to use this catalog for studying galaxy clusters having compound inner structure.
Determination of external GSS payload from light curves
(Одеський національний університет імені І. І. Мечникова, 2022) Sukhov, P. P.; Yepishev, Vitaly P.; Sukhov, Konstantin P.; Сухов, Петро Петрович
They are offered reflective features to external surface geostationary satellites on which possible identify the separate external construction geostationary satellites. Such constructions can be; the type and forms radio antennas, solar panels, thermo film on surfaces of the platform. They are given to recommendations and specified moments of time, condition, under which possible find the external payload. The paper presents the results of colorimetric observations of 5 GSS of multipurpose operation, on the platform of which an external payload in the form of several radio antennas was found, and in some cases the orientation and technical characteristics of the GSS were estimated.
Determination degradation of satellite surface optical features by photometric method
(Одеський національний університет імені І. І. Мечникова, 2022) Sukhov, P. P.; Yepishev, V. P.; Sukhov, K. P.; Pavlovskyi, Alexei L.; Mamrai, Sergei A.; Сухов, Петро Петрович
A method is described for using photometric data to estimate the reflective properties of a satellite's surface material under conditions of its long stay in space. The technique of multicolour photometric B,V,R observations of several geostationary satellites built on different types of tires is shown, and the results obtained over a period of 3 to 9 years. These are geostationary satellites Astra 2E (on the Eurostar E3000 bus), Azerspace- 2/Intelsat 38 (on the SSL-1300 bus), Sicral 2 (on the Spacebus-4000B2 platform) and Blagovest 11L (the Ekspress-2000 bus). It has been revealed that a pattern of change in the reflectivity of different geostationary satellites is dissimilar. Spacecraft materials used for the surfaces of geostationary satellites manufactured in the second decade of the 21st century are more resistant to the harsh space environment than those used for the satellites built in the late 20th century. We have proposed several ways of improving the method for identifying the spacecraft material type based on multicolour photometric observations. The presented results show that the proposed photometric method works and can be used for detecting spacecraft surface degradation.
Physical properties of “hot population” objects in the Kuiper belt
(Одеський національний університет імені І. І. Мечникова, 2022) Okhotko, H.; Troianskyi, V. V.; Bazyey, O.
Most planetesimals formed at distances of 15 - 30 a.u. were gravitationally ejected from the Solar system as a result of the migration of the giant planets, but a small part remained, captured by Jupiter and the Kuiper belt. As a result, we can now observe such a variety, in terms of physical and dynamic characteristics, in the Trojan asteroids of Jupiter and in the Kuiper belt. Planetesimals captured by the Kuiper Belt are a "hot population" now. The term "hot" does not refer to the temperature of bodies, but characterizes the orbit of objects. ~120,000 objects larger than 100 km. in diameter are known in the "hot population". This population is characterized by an orbital inclination greater than 5 degrees and a large eccentricity. The main task of the work, based on physical and dynamic characteristics, is to search for the same properties Trojan asteroids of Jupiter and objects from the "hot population" of the Kuiper belt, which supposedly migrated earlier from the region of the original orbit of Neptune. The data from ground-based observations and space missions is used in the work.
Observation of an occultation of the UCAC4 488-082551 star by asteroid (76228) 2000 EH 75 on 31 May 2022
(Одеський національний університет імені І. І. Мечникова, 2022) Gorbanev, Yuriy M.; Kleshchonok, V. V.; Kimakovsky, S. R.; Горбаньов, Юрій Михайлович
Observations of an occultation of the UCAC4 488-082551 star by asteroid (76228) 2000 EH 75 were carried out on 31 May 2022 at Kryzhanivka observation station of Odesa I. I. Mechnykov National University (the observatory code A85). A set of instruments, which included a Schmidt telescope (the primary mirror diameter D = 271.25 mm; the corrector plate diameter Dk = 223.9 mm; the focal length F = 440 mm), a GPS receiver and Videoscan-415-2001 CCD camera, was used to perform observations. The observing conditions were as follows: clear sky, the star’s altitude 490 south, the Moon was below the local horizon. The target star from the UCAC4 catalogue (Zacharias et al. 2013) has the following photometric parameters: mB = 14.008; mv = 12.720; mr = 12.284; m, = 11.813. The diameter of the star has not been determined. Asteroid (76228) is a Main Belt asteroid with an orbital period of 4.17178 years. It has an absolute magnitude of 14.93, the visible geometric albedo of 0.123±0.013 and diameter of 5.00±0.23 km (Masiero et al. 2011). The time of occultation predicted using ephemerides was 23:52:44±4 sec. The maximum duration of the occultation was 0.4 sec, provided that the observing site was located at the centre of the occultation track (strip). A drop in the star’s brightness observed during occultation was about 8m. The occultation event was recorded as a sequence of GIF images with the exposure time of 0.5 sec per frame. The system clock of the computer used for the occultation recording was controlled with a GPS receiver in a fashion similar to that described in the paper by Karbovsky et al. (2017). The data processing yielded an estimate of the occultation duration of 0.46±0.04 sec. The uncertainty of the occultation start time within exposure results in the total estimate of accuracy in timing the maximum phase of occultation 23:52:44.06±0.10 sec. The chord length across the asteroid estimated by timing the occultation is L = 9.2±0.8. This chord length is close to the estimates of the asteroid diameter reported in the paper by Masiero et al. (2011).
Refined physical properties of the HD 327083 binary system
(Одеський національний університет імені І. І. Мечникова, 2022) Nodyarov, A. S.; Miroshnichenko, A. S.; Khokhlov, S. A.; Zharikov, S. V.; Manset, N.; Usenko, I. A.; Усенко, І. А.
HD 327083 is a member of a small group of supergiants exhibiting the B[e] phenomenon. It was found to be a binary system with an early-B and an early-F supergiant components. However the fundamental and orbital parameters of the system were not accurately known. We determined a new set of the system parameters that include the orbital period and the components’ masses using a combination of photometric and spectroscopic data. A new orbital period of 107.7 days was found from both the spectral line positional variations and the visual light curve. Absorption lines of the cool component show a radial velocity semi-amplitude of 48.3 kms-1 , similar to that of emission lines that originate around the hot component. The system shows partial eclipses. We estimated the components’ masses to be nearly equal and close to 6-8 Mq . The masses turned out to be smaller then the evolutionary masses that may be a consequence of a recent mass-transfer.
From spectroscopy to the chemical evolution of the galaxy. Part 1.
(Одеський національний університет імені І. І. Мечникова, 2022) Mishenina, Tamara V.; Мішеніна, Тамара Василівна
A brief review of the results obtained at Odesa Astronomical Observatory based on the stellar spectra analyses from 1892 to 2000 is presented. The review begins with the first observations of emission lines in solar prominences carried out in 1892 under the direction of Alexander Kononowitsch and includes an overview of spectrophotometric studies performed at the observatory using instruments and telescopes designed inhouse; theoretical consideration of the issues of modelling physical conditions in stars and spectra simulation. It also describes the main results of the research of stars of various types, including cool giants K-, M spectral types, stars with various peculiarities of chemical composition, having enhanced lines of metals and CN bands, eclipsing binaries and binaries of different types, semi-regular and long-period variable stars, RR Lyraes, 5 Scuti and I Bootes stars, the diversity of Cepheids, blue stragglers in field and cluster populations, hot B Main-Sequence stars, etc., and finally, the enrichment with neutron-capture elements in the galactic stars.
An enigma of the Przybylski star
(Одеський національний університет імені І. І. Мечникова, 2022) Andrievsky, Serhii M.; Андрієвський, Сергій Михайлович
A new scenario to explain the Przybylski star phenomenon is proposed. It is based on the supposition that this star is a component of a binary system with a neutron star (similar to the hypothesis proposed earlier by Gopka, Ul’yanov & Andrievskii). The main difference with previous scenario is as follows. The orbits of the stars of this system lie in the plane of the sky (or very close to this plane). Thus, we see this star (and its companion) nearly polar-on, and therefore we cannot detect the orbital motion (spectral line based) from the Przybylski’s star spectrum. In relation to the Przybylski star, the neutron star is a γ-ray pulsar for it. A neutron star is a source of relativistic particles and radiation emitted from the certain parts of its surface. The topology of this radiation strongly depends on the the magnetic field configuration of the neutron star. Existing models suppose that 1) high-energy electron-positron pairs and hard radiation are produced in the (magnetic) polar zones. Accelerated charge particles that move along magnetic lines emit electromagnetic quanta. In this model the radio-emission is genetically linked with the emission of the γ-quanta. 2) Another model of the outer gap is based on the assumption that there is a vacuum gap in the outer magnetosphere of the neutron star, which arises due to the constant escape of charged particles through the light cylinder along the open magnetic field lines. The direction of such escape may be roughly orthogonal to the rotation axis. If the rotation axes of the Przybylski star and the neutron star are close in direction (or even aligned), charged particles and hard radiation ejected in the approximately orthogonal direction at a large solid angle can enter the Przybylski’s star atmosphere, causing there different physical processes. As a possible source of the free neutrons could be the nuclear reactions between high-energy γ-quanta and nuclei of some atoms in the Przybylski’s star atmosphere gas. As a result, photoneutrons can be generated. Large enough neutron flux can be produced in the reactions with quite abundant element of the atmosphere gas (for example, helium). The photoneutrons produced in these reactions are rapidly thermalized and, as resonant neutrons, react with seed nuclei in the s-process. It should be also noted that together with s-process elements, the deuterium nuclei could be formed as a result of the interactions of the free resonant neutrons with the hydrogen atoms, but this issue has not yet been worked out.
Application of photometry to understand the behaviour of geostationary objects on orbit
(Одеський національний університет імені І. І. Мечникова, 2021) Sukhov, Petro P.; Yepishev, V. P.; Motrunich, I. I.; Sukhov, K. P.; Сухов, Петро Петрович; Сухов, Петр Петрович
One of the challenges of satellite characterization is the ability to not only determine the spacecraft orbit, but also ssatellite operating status, orientation, size, bus type, and material properties. Positional observations allow us to determine and/or update orbital elements of satellites, but they do not afford an insight into the behaviour of a satellite in orbit. The article discusses the results of solving the inverse problem of astrophysics. How you can use photometric, astrometric information about a satellite, its lighting conditions, supplemented by additional information, to understand the behavior of a satellite in orbit. The results are shown using examples of four satellites in geostationary orbit. An algorithm for calculating the photometric and dynamic characteristics of geostationary objects is provided.
Monitoring the artificial space objects with Ukrainian network of optical stations
(Одеський національний університет імені І. І. Мечникова, 2021) Romanyuk, Ya. O.; Shulga, O. V.; Shakun, Leonid S.; Koshkin, Nikolay I.; Кошкін, Микола Іванович; Кошкин, Николай Иванович; Vovchyk, Ye. B.; Bilinsky, А. І.; Kozyryev, Y. S.; Kulichenko, M. O.; Kriuchkovsky, V. F.; Kashuba, V. I.; Korobeynikova, E. A.; Меlikyants, S. M.; Strakhova, S. L.; Теrpan, S. S.; Golubovskaya, T. A.; Martyniuk-Lototskiy, K. P.; Nogacz, R. T.; Epishev, V. P.; Kudak, V. I.; Neubauer, І. F.; Perig, V. М.; Prysiazhnyi, V. I.; Ozeryan, A. P.; Kozhukhov, O. M.; Kozhukhov, D. M.; Ivaschenko, Yu. M.
The article describes the successes and challenges of the Ukrainian network of optical stations (UMOS) in recent years in the field of astrometric observations of artificial space objects both in low-Earth orbit (LEO) and geostationary Earth orbit (GEO). UMOS was established in 2012 as a joint partnership of organizations interested in satellite observations for scientific purposes and practical near Earth space monitoring. The main purpose of the UMOS has been (and still is) to combine scientific and technical means with regular optical (positional and / or non-positional) observation. The short list of equipment of the UMOS members are given in the tables. The programs for observations, used methods and obtained results are described in the paper. In conclusion, the advantages of observations of artificial space objects by means of a network are summarized. The experience of UMOS and main results obtained by UMOS can be considered as the first step to create the SSA system of Ukraine
Spherical primary mirror in telescopes with complex (multi-element) optical designs
(Одеський національний університет імені І. І. Мечникова, 2021) Podlesnyak, S. V.; Fashchevsky, N. N.; Bondarenko, Yu. N.; Andrievsky, Serhii M.; Андрієвський, Сергій Михайлович; Андриевский, Сергей Михайлович
An optical design for telescope with spherical primary mirror, planoidal surface and two-lens corrector is discussed. The spherical mirror has an aperture ratio 1/2.69. After reflection from the spherical mirror, the wave front falls on a planoidal surface and “forms” the reflected wave front from a virtual mirror with e2 = 1.576. After passing the two-lens corrector, the light is collected in the focal plane. A dot diagram in the focal plane shows that all three-order aberrations are successfully corrected. The effective field of view is 2 degrees. The aperture ratio is 1/2.28.
Actinium abundances in stellar atmospheres
(Одеський національний університет імені І. І. Мечникова, 2021) Yushchenko, V. A.; Gopka, Vera F.; Yushchenko, A.; Shavrina, A.; Pavlenkо, Ja.; Vasil’eva, S.
This paper presents a study of radioactive actinium in the atmospheres of stars located in galaxies with different chemical evolution history – namely, Przybylski's Star (HD 101065) in the Milky Way and the red supergiant PMMR27 in the Small Magellanic Cloud; it also reports the findings of the previous research of the red supergiant RM 1-667 in the Large Magellanic Cloud and the red giant BL138 in the Fornax dwarf spheroidal galaxy. The actinium abundance is close to that of urani um in the atmospheres of certain stars in the Milky Way’s halo and in the atmosphere of Arcturus. The following actinium abundances have been obtained (in a scale of lg N(H) = 12): for the red supergiants PMMR27 and RM 1- 667 lg N(Ac) = -1.7 and lg N(Ac) = -1.3, respectively, and for the red giant BL138 lg N(Ac) = -1.6. The actinium abundance in the atmosphere of Przybylski's Star (HD 101065) is lg N(Ac) = `0.94±0.09, which is more than two orders of magnitude higher than those in the atmospheres of the other studied stars.
Spectroscopic investigations of galactic open cluster Collinder 394 – new results
(Одеський національний університет імені І. І. Мечникова, 2021) Usenko, I. A.; Kniazev, A. Yu.; Miroshnichenko, A. S.; Danford, S.; Kovtyukh, Valery V.; Mishenina, Tamara V.; Мішеніна, Тамара Василівна; Мишенина, Тамара Васильевна
Confident main-sequence (MS) members of the Collinder 394 open cluster are perfect objects to check the correctness of their distances, obtained from the GAIA GR2 (2018) catalogue. The differences in the distances to the open cluster Collinder 394, determined by photometry and from the GAIA parallaxes have raised doubts about the correctness of the latter. Therefore we used spectroscopically determined Teff and log gvalues for these stars from Usenko et al. (2019) and tried to solve the inverse problem: determine radii of these stars using the derived distances and calibrations “Teff-radius” for MS stars and compare with similar ones. For this purpose we used the calibrations from Torres et al. (2010), based on the nearest MS eclipsing binaries and compilations for MS stars from Mamajek (2018). As a result, we obtained relationships that connect Teff, log g, radii, masses, and distances for the confident Collinder 394 MS stars. We have confirmed the correctness of the GAIA DR2 (2018) distances for these stars and determined their radii and masses. The latter estimates turned out to be close to those of the evolutionary masses calculated by the PARSEC models.
The 3-D numerical simulations of the dependence of the disk structure from the wind configuration in one-point in microquasar CYG X-1. The case of the high resolution grid in the vertical direction
(Одеський національний університет імені І. І. Мечникова, 2021) Nazarenko, V. V.
The present paper is devoted to the investigation how the disk structure is depending from the one-point wind one in microquasar CYG X-1. The results show that when the region in which the wind is absent in the vicinity of one-point has the size less or equal to 0.07 the disk radius is very small, order of 0.08 in units of orbital separation. When this size is increased to 0.115 the disk radius becomes to be of standard size to be equal to 0.22 in units of orbital separation. By the other words these results show that the disk structure is strong depending from many factors including and the donor’s wind configuration in the vicinity of one-point. This configuration is inherent to microquasars only. Indeed, since microqausars are the massive close binary systems; the donor in these systems is massive star from which the strong radiationdriving wind is blowing. On the other hand, in microquasars accretion disks are present and it means that one-point stream is also present in microqausars. It in turn means that the matter configuration in the vicinity of one-point is very complicated since the high mass loss rate donor’s wind and one-point stream must be existing in the vicinity of one-point simultaneously. This situation maybe resolved when we suppose that the central source in an accretion disk will influence on the donor’s atmosphere structure in the vicinity of one-point and in turn will be result in the break of wind in the vicinity of one-point. This finally will be means that one-point stream will be existing in onepoint without a wind and it, flowing in the accretor’s Roche lobe, will be result in an accretion disk formation. Here one problem is arising: what is the config uration of wind in the extended vicinity of one-point and from what the parameters this configuration is depending and haw this configuration will be results to the disk structure change. We good understand that this situation is arising in the case of microquasars only and we try to resolve this problem in the present paper.

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