Posters

  Efficient technique for precise orbit integration of Earth satellites

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Szucs-Csillik, I., Turcu, V.

Romanian Academy, Astronomical Institute, Astronomical Observatory Cluj-Napoca

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Thousands of satellite missions are orbiting the Earth. For the analysis of the satellite mission and the design of its trajectory, as well as for the directing, guidance and navigation of artificial satellites, it is necessary to be able to calculate the most accurate forecasts. On the other hand, the Newtonian equations of motion in rectangular coordinates become singular when the distance between the two bodies, regarded as point masses, tend to zero (close encounter). Numerical integrations provide several advantages over classical Newtonian equations, but in the case of close encounters, it is better to use the KS-regularization to study the satellite motion. To avoid the singularity, we used the regularization technique, introducing coordinate transformation to blow up the motion around the singularity and time transformation to slow down the motion. The resulting new, linear and regular second-order differential equations of motion can be used to obtain precise solutions. The precise orbit prediction of the artificial satellite’s motion depends on correct initial conditions and from an adequate numerical (canonical) integrator. The analytical and numerical part of the presented efficient technique is emphasized with a concrete application for Leo satellites.

Szucs-Csillik, I. (1), Mansur, A. (2), Shoaib, M. (3), Offin, D. (4),

Brimberg, J.  (5)

(1) Romanian Academy, Astronomical Institute, Astronomical Observatory Cluj-Napoca
(2) College of Science, Bani Waleed University, Bani Waleed, Libya, and Engineering and Information Technology Research Center, Bani Waleed, Libya
(3) Smart and Scientific Solutions, 32 Allerdyce Drive, Glasgow, G15 6RY, United Kingdom
(4) Queen's University, Mathematics and Statistics department, Kingston, Ontario, Canada
(5) The Royal Military College of Canada, Mathematics and Computer Science department, Kingston, Ontario, Canada

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The orbits of stars conserve information about the formation processes of the multiple star systems, and exploring dynamically their motion helps us to understand the evolution of stars. Accordingly, special types of the four-body problem investigated analytically and numerically can provide a better understanding of the dynamical behavior of quadruple stellar systems. This paper deals with the isosceles trapezoidal four-body problem (I4BP), where two point masses are equal with 1, while the remaining two point masses are equal with m. Consider these four point masses on the vertices of a trapezoid. Let us take the distance between the first two bodies to be 1, and between the last two bodies equal to a, and the first two particles lying on the x-axis. The length of each side is b. The position of the bodies can be marked as follows r_1(−1/2, 0), r_2(1/2, 0), r_3(a/2, (b^2−(1−a)^2/4)^1/2), and r_4(-a/2, (b^2−(1−a)^2/4)^1/2). Hence, the time evolution of the system is uniquely defined by the geometrically reduced Hamilton’s equations. Further, we studied the minimizing property of the solutions and demonstrated that the minimizers of the action functional restricted to homographic solutions are the Keplerian elliptical solutions, and this functional has a minimum. In addition, we investigated the dynamical behavior of the isosceles trapezoidal four-body problem using the surface of section method.

T. Hegedüs (1,2) , Z. Jäger (1), Z. Goda (3), Zs. Kereszty (2), Á. Lang (4), L. Papp (5) 
(1) Baja Observatory of the University of Szeged 
(2) Hungarian Meteoritics Society 
(3) Faculty of Water Sciences of the University of Governmental Services 
(4) Faculty of Wood Engineering and Creative Industries of the University of Sopron 
(5) APRS Hungarian Node, radio amateur HG8LXL, Csongrád

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Owing to the coordinated cooperation of the consortium of a few institutions and private partners, some special "planetary defense" and "near space" services are available by requests since 2023. First, a new, independent fireball observing network was installed and tested in 2022. Practically the whole atmospheric region over Hungary is covered up to 100-110 km by 6 stations. Each station is used in automatic operation mode, but has local technical assistance. The camera heads consist of 7 (in the case of latest installation 8) identical camera+lens combo, GPS sensor, and weather-proof acrylic dome. The local control is done by a mini-PC at the sites, but all these stations are part of the whole-earth "allsky7" system. The main aim is to produce more accurate luminous atmospheric orbits for the brightest bolides and supply better initial parameters for dark flight calculations, resulting in a better chance to uncover the possible strewn fields of future events. The DAMBALL high-altitude balloon group and SOPROBOTICS team continued the "intelligent" artificial meteoroid drop experiment. The on-flight communication and crash tests are done, now the final tests are on the way (wind-tunnel tests and the remote-controlled drop-down mechanics). The group offers near-space test opportunities for any interested space technology-related entities for flight-tests of any instruments - within a given size-, and weight limit (the maximum is about 1 kg which can be lifted over 25 km). The expected time for near-space tests is about 30 minutes (this is the average time of the gondola complex being above 25 km height), but uncontrolled.

Octavian Blagoi, Liliana Dumitru, Cristian Adrian Danescu 
Astronomical Institute of the Romanian Academy

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The solar radio bursts are electromagnetic spectrum emissions from the solar corona, caused by several different phenomena, linked with the solar activity in other solar atmospheric regions. We study a type II radio burst following a M3.7 class flare, which occurred in the active region AR13229 on February 24th 2023. We present our work to install and use the CALLISTO instrument and types of solar radio burst recorded at the Bucharest experimental station.

Liliana Dumitru, Octavian Blagoi, Cristian Adrian Danescu 
Astronomical Institute of the Romanian Academy

 

Using a nonlinear force-free field (NLFFF) algorithm, we calculated the magnetic flux around M3.7 class solar flare produced by Active Region 13229 (AR 13229), located in the northern solar hemisphere (N29W24), on February 24, 2023. The solar flare is associated with a filament eruption, and these phenomena produced a coronal mass ejection with an earth-directed component. Also, we obtained the 3D magnetic configuration from photospheric magnetic magnetograms Space Weather HMI Active Region Patch (SHARP) from the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO).

Dana Ficut-Vicas, Vlad Turcu 
Astronomical Observatory of Cluj-Napoca, Romanian Academy

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We present the state of development of Radio Astronomy in Romania and the technical capabilities Romania has to make its contribution to the international radio astronomy infrastructure and research. We discuss the need for forthwith actions towards opening and developing the field of Radio Astronomy in our country.

Szucs-Csillik, I. (1), Poputa, D. (2), Braun, K. (3)

(1) Romanian Academy, Astronomical Institute, Astronomical Observatory Cluj-Napoca

(2) „Lucian Blaga” Central University Library of Cluj-Napoca, Library of Astronomy, Astronomical Observatory of Cluj-Napoca
(3) Astronomical Observatory Baja, Hungary

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Since the advent of online digital journals and e-books, as well as the decrease in the number of new books and scientific journals, many specialized libraries have lost readers in various fields. The Astronomical Libraries located in Cluj-Napoca and Baja Astronomical Observatories also face this problem. In order to attract readers, especially students, the Astronomy Library organizes open days together with researchers and professors, during which the library, the publications, and some current issues of observational and theoretical astronomy are presented. Students interested in astronomy show an increasing interest in the open days of the Astronomical Observatory, as these days usually are related to an interesting astronomical phenomenon. This paper deals with the problem of a "not worked at full throttle" astronomical library and presents the Astro-Biblio-Students program as a possibility to improve this situation.

Remus Boata
Astronomical Observatory Timisoara, Romanian Academy Timisoara Branch, Romania

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The fuzzy methods represent an alternative to the statistical approach for modeling the real phenomena from nature. These techniques facilitate a realistic approach and have been used for modeling solar radiation. This study proposes a new hybrid method, based on combined statistical-fuzzy methods, as an alternative to the models constructed using only classical statistics methods or only fuzzy sets theory. The aim of this combination is to improve the accuracy of solar irradiation estimation and the results demonstrate that the new hybrid model can contribute to efficient estimation of solar irradiation.

Violeta Poenaru (1), Mirela Bivolaru (1), Vlad Turcu (2)

(1) Romanian Space Agency

(2) Astronomical Observatory, Romanian Academy Cluj-Napoca Branch

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In the ever-evolving landscape of satellite technology, the ability to effectively monitor and predict the trajectories of space objects is imperative. There is an escalating concern regarding the congestion of the space environment resulting from an increasing number of satellites, which poses risks of collision and the generation of space debris. Consequently, several countries and organizations have dedicated efforts to enhance space situational awareness. European entities, including the European Space Agency (ESA) and European Commission, have made significant strides in implementing projects focused on the developing algorithms and systems for efficient maneuver detection and automated collision avoidance. 
In Romania, a burgeoning interest and investment in space sciences have been evident. With an evolving national strategy aimed at boosting its space capabilities, Romania has been an active participant in various European space programs. Romanian academic institutions and research centers have been conducting cutting-edge studies focusing on the development of a system capable of acquiring data, monitoring and analyzing a space environment. 
This paper presents a comprehensive comparative analysis between Two-Line Elements (TLEs) and the pre-maneuver and post-maneuver orbital data collected by Romanian optical sensors. TLEs, as widely-adopted means of representing satellite orbit data, are advantageous due to their accessibility and standardized format. However, TLE data accuracy is often constrained by simplistic models and inconsistencies in propagation methods. By meticulously examining these distinct datasets, the study aims to uncover nuanced relationships, assess the accuracy and reliability of TLEs, and shed light on the performance of Romanian optical sensors in capturing orbital information during critical pre-maneuver and post-maneuver phases. This thorough examination and comparison of the data sources will provide valuable insights, fostering a deeper understanding of the strengths, limitations, and potential synergies between TLEs and the Romanian optical sensors data.