Precise positions of Triton in 2010–2014 based on Gaia-DR2

With unique orbital and physical characteristics, Triton is a very important target since it may contain information of the origin and evolution of the solar system. Besides space explorations, ground-based observations over long time also play key role on research of Triton. High-precision positions of Triton obtained from ground telescopes are of great significance for studying its orbital evolution and inverting the physical properties of Neptune. As a long-term observational target, Triton has been observed by the 1.56 m telescope of Shanghai Astronomical Observatory since 1996. In this paper, based on our AAPPDI software and with Gaia DR2 as the reference catalogue, 604 positions of Triton during 2010-2014 are calculated, with standard errors of $19mas-88mas$. A comparison between our results and the ephemeris (DE431+nep096) is also given.

An all-sky camera images classification method using cloud cover features

The all-sky camera (ASC) images can reflect the local cloud cover information, and the cloud cover is one of the first factors considered for astronomical observatory site selection. Therefore, the realization of automatic classification of the ASC images plays an important role in astronomical observatory site selection. In this paper, three cloud cover features are proposed for the TMT (Thirty Meter Telescope) classification criteria, namely cloud weight, cloud area ratio and cloud dispersion. After the features are quantified, four classifiers are used to recognize the classes of the images. Four classes of ASC images are identified: “Clear”, “Inner”, “Outer” and “Covered”. The proposed method is evaluated on a large dataset, which contains 7328 ASC images taken by an all-sky camera located in Xinjiang (38.19° N, 74.53° E). In the end, the method achieves an accuracy of 97.28 % and F1_score of 96.97 % by a random forest (RF) classifier, which greatly improves the efficiency of automatic processing of the ASC images.

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.

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.

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.

Design and construction of hardware and software for autonomous observations of Transient Luminous Events

Transient luminous events (TLE) are phenomena which are currently on the rise in terms of sightings. However, there is no widespread uniform method of their observation and subsequent image processing. Therefore, our project focuses on the design and construction of hardware that can record TLE. It consists of a low gain, colour, CMOS camera with a bright, wide lens connected to a small, power-efficient single board computer. The project also includes writing software to control the hardware. The software decides whether to capture or not and at what orientation there is the biggest chance to capture a TLE. The software can process and classify the created photos based on deep neural networks. As a final product, we have developed the whole apparatus from a hardware and software point of view and installed it at the Astronomical Observatory at Kolonica Saddle in Slovakia, Central Europe. The plan for the future is to make similar apparatuses to spread the observation network.

Yuri Gagarin public astronomical observatory – the first in Bulgaria: 60 years later

The report presents an analysis of the history of the Public Astronomical Observatory (NAO) "Yuri Gagarin", the city of Stara Zagora, which was officially opened on February 26, 1961. The initiative to open it belongs to a group of enthusiasts, among which the figure of Boncho Bonev is of particular importance. With financial and material assistance from the municipality of Stara Zagora, the first premises were equipped and the first astronomical instruments and equipment were purchased. The observatory bears the name of the world's first pilot - cosmonaut Yuri Gagarin. The natural evolution of the development of the Observatory is presented, as well as the need of creation an observational base outside the city, in the area of the Ayazmo Park (opened in 1968). The supply with amateur telescopes is shown, as well as of a large optical instrument for professional astronomical work – a refractor (200/3000 mm), the Kude system, the production of the Carl Zeiss, Jena (former East Germany). The acquired ZKP-2 planetarium at the Carl Zeiss factory in Jena expands the NAO's capabilities in the education and promotion of astronomy and space science.The evolution of extracurricular astronomy training and the mass popularization of the achievements of astronomy, aeronautics, physics and human technology in PAOP are analyzed, as well as scientific observations of artificial Earth satellites. In this connection, in 1979 a specialized out-of-town observation base was built in the area of the Stara Zagora Mineral Baths, equipped with one of the most modern devices of its time – the AFU-75 satellite camera. An attempt was made to periodize the history of PAOP «Yu. Gagarin», the main stages being arranged in time according to significant historical, technological, organizational or other events.

History and activities of the Kourovka astronomical observatory of the Ural university

The history of origin and scientific activities of the suburban Astronomical Observatory of the Ural University are associated with K.A. Barkhatova’s life and work, among her achievements were restoration of the Department of Astronomy and Geodesy in 1960, and the resumption of the training of specialists in astronomy and geodesy. The First satellite launch on October 4, 1957 was great stimulus for the opening of department. A station for optical observations of satellites was organized in Sverdlovsk. Successful scientific and academic work of the department required a modern, properly equipped suburban observatory. Yu.A. Gagarin flight around the Earth on April 12, 1961 aroused unprecedented interest in astronomy and space among people and accelerated the resolution of the issue of an observatory construction. K.A. Barkhatova, with the support of colleagues from the Astronomical Council of the USSR Academy of Sciences, other observatories of the country, rector of the Ural University, and the public took up the construction. In 1963 the observatory near Kourovka station was founded. January 12, 1965 is considered to be the birthday of the new observatory. K.A. Barkhatova was it’s scientific adviser; at present, the observatory is named after her. The observatory performs observations on modern equipment, conducts excursions for students, teachers and public. Each year, the observatory hosts a student scientific conference "Physics of Space" – a unique astronomical school for young students and graduate students.