EARLY KYIV OBSERVATIONS OF ASTEROIDS: ANALYSIS AND NEW REDUCTION WITH TYCHO-2 AND GAIA CATALOGS

For more than 50 years, the continuous photographic observations of asteroids have been carried outwith telescopes of the Astronomical Observatory of the Taras Shevchenko National University of Kyiv and the Main Astronomical Observatory of the National Academy of Sciences of Ukraine. About 3,000 photographic plates were obtained, some of which were exposed in 1908. We collected the data on more than 5,500 positions and magnitudes of asteroids on these astroplates taking into account all results of the processing of observations available in various publications and in the Minor Planet Center database. All positional data were compared with JPL ephemeris and analyzed. From different series of asteroid observations the values of positional accuracy were obtained, depending on the methods of measuring and processing the plates and reference catalogs of stars. In order to systematically improve the obtained asteroid positions, we evaluated the possibilities of reprocessing some of the earliest asteroid observations applying the modern star high accuracy catalogs. Using the Tycho-2, Gaia DR2, and Gaia EDR3 as the reference catalogs, the 590 astroplates exposed on the MAO NASU Double Long-Focus Astrograph (DLA) in 1952-1986 were reprocessed based on old plate measurements. All newly determined and previous original asteroid positions were compared with the JPL ephemeris. The comparison results show an improvement in the systematic and random components of the accuracy of coordinates for new positions of asteroids. When comparing the new positions of the asteroids determined in the Tycho-2 and Gaia catalog systems, no significant changes in accuracy were found.

THE 3-D NUMERICAL SIMULATIONS OF THE SMALL RADIUS ACCRETION DISK FORMATION IN MICROQUASAR CYG X-1. THE CASE OF THE HIGH RESOLUTION GRID IN THE VERTICAL DIRECTION

The present paper is devoted to small radius accretion disk formation in microquasar CYG X-1. The results show that in the case of the strong wind action on a disk the disk radius is about of 20 ÷ 30 per sent of accretor’s Roche lobe radius (it is about of 0.08 of orbital separation) instead of the standard disk radius equal to 80 ÷ 85 per sent of accretor’s Roche lobe radius (the last magnitude is a disk radius equal to 0.22 of orbital separation). In the present paper we try to resolve the problem that is arising in the case of microquasars when we investigate the accretion disk formation in these objects. Indeed, since the microquasars are the massive close binary systems (MCBS) in which the donor is massive stars of O-B class the strong wind is blowing from these stars. In this case the problem is arising: what is the situation in which an accretion disk in microqausars is formed. By the other words, it means what are the processes and the matter that are responsible for an accretion disk formation in microquasars: is this matter from one-point stream only or a disk is formed from the donor’s wind in essential or one is formed from both processes simul- taneously. This question is not idle since one is strong affects on ON-OFF state generations in the precession mechanism model. Since this mechanism is strong depending from the magnitude of the disk centre density and all the parameters affecting on it are very important for calculations. The matter configuration in the vicinity of one-point is one of these parameters that strong affects on ON-OFF state production and disk structure and the central disk density. By this reason we have investigated in the present paper how the disk structure is depending from the wind configuration in the vicinity of one-point.

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

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 radiation- driving 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 one-point without a wind and it, flowing in the accretor’s Roche lobe, will be result in an accretion disk forma- tion. Here one problem is arising: what is the configuration 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.

ACTINIUM ABUNDANCES IN STELLAR ATMOSPHERES

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 uranium 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.

SPHERICAL PRIMARY MIRROR IN TELESCOPES WITH COMPLEX (MULTI-ELEMENT) OPTICAL DESIGNS

An optical design for telescope with spherical primary mirror, planoidal surface and two-lens corrector is discussed. The spherical mirror hasn 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 e 2 = 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.

OBSERVATION CONTROL DEVICE FOR THE URAN-4 DECAMETER RADIO TELESCOPE

The URAN-4 radio telescope has been operating at the Odessa Radio Astronomy Observatory of the Radio Institute of the National Academy of Sciences of Ukraine since 1986. The telescope is an element of a decameter long-base interferometer – the radio telescopes which are located across the territory of Ukraine from west to east. The URAN-4 consists of antenna and upgraded radiometer. Antenna consists of 128–element with phased array with dimensions of 232.5 x 22.5 m. The telescope operates in the 10 – 30 MHz range. Its receiving equipment is capable of separating two polarization components of the received signal. The radiation pattern of the radio telescope is 2,7x22 degrees at 25 MHz. The resolution of 2 seconds is realized in the interferometer mode. The instrumental complex of the radio telescope includes the upgraded device for controlling its operation. This device is made in the form of a separate unit. The ATMEL AT90S8515 microcontroller with registers and a communication circuit between the unit and the computer are mounted in it. The discrete movement in space of the antenna's directional pattern and sets the required attenuation in the attenuator during calibration are carried out with the upgraded controlling device at a given time during the observation period. The controlling device also allows adjust the current time of the computer using GPS.

FON DUSHANBE CATALOGUE. RESULTS OF PROCESSING IN THE TYCHO-2 SYSTEM

In the Tycho-2 catalogue system the processing of 1529 photographic plates of the FON Dushanbe project from the collection of the Institute of Astrophysics of the National Academy of Sciences of Tajikistan was completed. The photographic plates with the size of 8º×8º (30x30 cm) were exposed in the zones from -8º to + 84º in the period of 1985-1992 years. In years 2017 – 2020 the plates were digitized using a Microtek ScanMaker 1000XL Plus scanner with the resolution of 1200 dpi, so the size of the digitized images is near 13000x13000 px. Based on the results of the processing of digitized images a catalogue of equatorial coordinates α, δ and B-magnitudes of stars for the northern hemisphere of the sky was created. The catalog contains about 30 million stars and galaxies for the epoch 1988.74. The average internal accuracy of the catalogue for all objects is σαδ = ±0.32" and σB = ± 0.11 m (for stars in the range of B = 8 m -14 m the errors are σαδ = ±0.19" and σB =±0.07 m ) for equatorial coordinates and B-magnitudes respectively. The convergence between calculated and reference positions from the Tycho-2 catalogue is σαδ = ±0.07" and the convergence with photoelectric B-magnitudes is σB = ±0.16 m . Five astronomical institutions took part in the processing of the photographic plates and in the creating of the FON-Dushanbe catalogue: Institute of Astrophysics of NAS of Tajikistan; Walter Hohmann Observatory, Essen, Germany; Ulugh Beg Astronomical Institute UAS, Uzbekistan; Research Institute “Mykolaiv Astronomical Observatory”, Ukraine and Main Astronomical Observatory NASU, Ukraine.

FIRST RESULTS OF PROCESSING DIGITIZED V-PLATES TAKEN WITH THE TAUTENBURG 2m SCHMIDT TELESCOPE

The process of treatment of about 500 digitized plates has started in MAO NAS of Ukraine. Plates were taken with the Tautenburg 2m Schmidt telescope in 1963-1989. Linear dimensions of plates are 24x24 cm with a working field of 3.3x3.3 degrees and a scale of 51.4 "/ mm. Astronegatives were digitized on the Tautenburg Plate Scanner in five strips with linear dimensions of 5 400x23 800 px. The software developed in MAO NAS of Ukraine for the image processing of these scans takes into account the horizontal overlap and the vertical offset of strips. The photometric range of fixed objects is 12 magnitudes, around V = 7 m - 19 m , due to the separation of objects into faint and bright parts by their images’ diameters. Positions of stars and other fixed objects are obtained in the GAIA DR2 reference system. Magnitudes are defined in the V-band of the Johnson color system. The resulted positional accuracy defined from 180 plates’ processing is σ RA,DEC = 0.10"for both coordinates, photometric error on the whole range of magnitudes is σ V = 0.14 m . The convergence of resulted magnitudes with ones from photoelectric standards’ data is 0.19 m . In parallel with image processing and plate data reduction, the search for minor planets’ images was carried out. Nine positions and magnitudes of 4 asteroids registered on the plates obtained in 1963-1965 were defined and used for further analysis.

ASTROMETRIC RESEARCH IN UKRAINE AT THE XIX – BEGINNING OF XX CENTURIES

The paper presents the stages of development of astrometric research at the Ukrainian observatories in the ХIХ – beginning of ХХ century. They are related to the establishment of university astronomical observatories in Kyiv (1845), Odessa (1871), Kharkiv (1888). Mykolaiv Naval observatory was founded in 1821 for navigation needs with assistance of Admiral A.S. Greig. The absolute catalogs compiled at the Pulkovo and Mykolaiv Observatories made a significant contribution to the international work of compilation of a FK3 system. Special attention is paid to the scientific activity of the oldest observatory at the territory of Ukraine – the Astronomical observatory of L’viv University (1771). Researches at this observatory were mainly concerned with the field of geodesy and meteorology. Despite the short first period of scientific activity (near 10 years), it gave impetus to some famous scientists. At the last decades of ХIХ century observatory of the L’viv University renewed their activity in astrometry, solar physics, and astrophysics. Southern departments of Pulkovo observatory in Odessa (1899) and Mykolaiv (1912) played an important role in extension of Pulkovo absolute catalogues to the southern hemisphere. Systematic observations of the Sun conducted at these departments contributed to the more precise determination of the position of vernal equinox. In ХIХ century Ukrainian observatories participated in the international programs, such as AGK (Astronomischer Gesellschaft Katalog), the photographic catalog “Carte du Ciel” (France). Among the actual observational programs were surveys of zodiacal stars (M.P.Ditchenko in Kyiv), near-pole stars (V.I.Fabritius, R.P.Fogel, M.P.Ditchenko in Kyiv, L.O.Struve and K.N.Kuz'menko in Kharkiv, I.O.Djukov, L.F.Cherniev in Odessa). In the frame of observations of Bonner Durchmusterung (BD) and its southern continuation, organized by the German Astronomical Society, observations of the equatorial zone were provided by I.E. Kortazzi at Mykolaiv observatory, B.V.Novopashenny at the Astronomical Observatory of Odessa University in 1930s years. Needs of astrophotography lead to the creation of the “Сatalog of the faint stars” project. In 1932 at the First Astrometric Conference in Leningrad, the Pulkovo astronomers Gerasimovich B.P and Dniprovsky M.I. suggested the idea of using eхtragalactic nebulae as the reference objects for determination of the absolute motion of the stars. Among the tasks to be solved at the project was compilation of a general catalogue (KSZ) and a fundamental catalog of faint stars (FKSZ). It was planned to involve all the meridian instruments of the USSR as well as foreign ones, especially in the southern hemisphere. The idea of orientation of the KSZ coordinates system related to the observations of small planets was suggested by B.V.Numerov. Astronomers of Mykolaiv Astronomical Observatory participated in the international part of this project (AGK3R-catalogue). The Poltava gravimetric observatory was founded by A.Ya.Orlov in 1926 to construct a gravity map of the territory of Ukraine and to establish astrometric research, earth tides, and Latitude Service with zenith-telescopes. The main research fields of the Main Astronomical Observatory of the NAS of Ukraine, founded by A.Ya.Orlov in 1944, were related to the positional and photographic astrometry during the first decade of its work. We defined three “genealogical scientific trees” of astrometric schools. Two of them were formed under the leadership of outstanding personalities of the XX century: Prof. Alexander Ya. Orlov (the founder and first director of the Observatory, 1944–1948, 1950–1951), who moved to Kyiv from Poltava, and Prof. Avenir A.Yakovkin (director of the Observatory in 1952–1959), who moved to Kyiv from Kazan. The third genealogical tree has grown from the Pulkovo astronomical school. Formation of main directions of scientific researches and its transformation are also discussed. Keywords: astrometric research, positional astrometry, photographic astrometry, fundamental astrometry.

CONNECTION OF THE INTENSITY OF THE FLUX OF SCR PROTONS WITH THE VELOCITY OF THE CME AND WITH THE FADING OF THE RADIO EMISSION OF THE SUN IN THE DECAMETER RANGE

The relationship between SCR and CME and with fading of the continuum of noise storms and typeIV radio bursts in the decameter range is investigated. It was shown earlier that about 60% of CMEs associated with solar proton events are accompanied by deep fading of the solar radio emission in the decameter range, which coin-cides in time with CME registration. It has also been shown that fading is characterized by fading depth, the frequency bandwidth in which the fading occurs, as well as the duration of the fading and the frequency at which the maximum fading depth is observed. Further detailed studies have shown that for proton events accompanied by fading of the solar radio emission in the decameter range, the relationship between the intensity of the SCR proton flux and the CME velocity is much worse than for events without fading of the solar radio emission in the decameter range. However, it was foundthat for such events, the relationship between the flux of SCR protons and the CME velocity significantly increases if we take into account the fading depth of the solar radio emission in the decameter range.Earlier in (Isaeva, 2019), the results of a study of the relationship between the intensity of fading of the continuum of noise storms with the parameters of X-ray bursts, with the CME velocity and the velocity of coronal shock waves, as well as with the intensity of the SCR proton flux were presented. This paper presents the results of studying the relationship between the intensity of the SCR proton flux withthe parameters of type II and IV radio bursts, as well as with the CME velocity and with the velocity of coronal shock waves, depending on the intensity of fading of the solar radio emission in the decameter range at a frequency of 27 MHz. The frequency of 27 MHz was chosen because in the region of this frequency the maximum fading depth of the solar radio emission in the decameter range is observed.