Papers by Endang Soegiartini
Proceedings of the International Astronomical Union, 2019
Youths and kids in Indonesia since almost two decades ago have been showing significant increase ... more Youths and kids in Indonesia since almost two decades ago have been showing significant increase of interest in space sciences, especially astronomy. One of the main factors is due to the annual event of National Science Olympiad which includes Astronomy as the subject. The increasing level of public interest, especially younger generation on astronomical events, such as eclipses, moon sightings, meteor showers has been constantly observed from time to time. Being aware that Astronomy course does not included in primary and secondary education level’s curricula, teachers are somewhat desperate and are not capable to play role as clearing house in science related to space. The IAU Network of Astronomy for School Education Network (IAU-NASE) course was started in 2016 in Machung University, East Java as the pilot project in Indonesia. The course has attracted significant interest from teachers and university staff, especially in East and Middle Java Provinces. Being confident with the...
European Journal of Physics, 2021
The result of the only known good quality observations of September 18, 2017 Venus occultation by... more The result of the only known good quality observations of September 18, 2017 Venus occultation by the Moon is presented in this article. This kind of observation can be done by students using a common camera, and the analysis can be designed as a mathematics and physics exercise. Several observations were carried out in Malang and Jakarta, but high quality data were obtained only in Jakarta. An analysis of the occultation geometry then showed that the shortest distance between Venus and the center of the Moon disk was 249 arcsec. We were also able to fit the occultation light curve with a simple geometric model using an additional correction factor (1 + sin2 ϕ) to compensate for the hill-shaped intensity variation in the Venus disk. Video Abstract: A simple magnetic oscillator-rotator model made of magnetic balls, and its examination by video-analysis
arXiv: Earth and Planetary Astrophysics, 2013
Asteroid 1934 CT;1989 AC, well known as 4179 Toutatis, is an Apollo and Mars-crosser asteroid wit... more Asteroid 1934 CT;1989 AC, well known as 4179 Toutatis, is an Apollo and Mars-crosser asteroid with a chaotic orbit produced by a 3:1 resonance with Jupiter and a 1:4 resonance with the Earth, and frequent close approaches to the Earth. It is listed as a potential hazardous object (PHA). The aim of this study is to investigate the possibility of 4179 Toutatis to be ejected from the Solar System. This paper presents an orbital evolution of 4179 Toutatis in time interval of ~300 kyr. Investigation of its orbital evolution is conducted by using the Mercury subroutine package, where the gravitational perturbations of eight major planets in the Solar System are considered. Over very short time scales (~300 kyr) relative to the Solar System life time (~10 Gyr), the asteroid 4179 Toutatis gave an example of chaotic motion that can cause asteroid to move outward and may be followed by escaping from the Solar System.
Journal of Physics: Conference Series, 2020
The study of orbital dynamics and evolution of Solar system small-bodies like asteroids has been ... more The study of orbital dynamics and evolution of Solar system small-bodies like asteroids has been conducted regularly with the latest data to ensure and update our understanding of the object’s motion, especially the ones located nearby the Earth. One of its examples is asteroid 469219 Kamo’oalewa, which currently known as an Earth Quasi-satellite (QS). In this article, we investigate the orbital dynamics of 469219 Kamo’oalewa by running an N-body numerical integration. It was calculated from its latest orbital solution at epoch JD 2458600.5 using Gauss-Radau scheme provided by IAS15 integrator, which available on REBOUND code package. We found that the co-orbital motion of the asteroid towards Earth happens during time interval (–19.7,19.5) thousand years, with QS–HS transition happening at that period. The current QS motion started 15 years ago and will be transitioning to HS at around 50 years from now. After losing its current state, it will orbit the Sun near the Earth as an Apo...
Journal of Physics: Conference Series, 2019
Night sky brightness (NSB) research related to the artificial light pollution issues has been inc... more Night sky brightness (NSB) research related to the artificial light pollution issues has been increasing all over the world, using various measurement techniques and tools. The research produces tens of thousands of data for each month such that proper handling, processing and analysing the data become challenging. In this article, we demonstrate an alternative method for processing the NSB data by utilising pattern recognition techniques: Canny edge detection and Hough transform. These techniques were applied to identify data and extract important parameter from the NSB density plot semi-automatically. Datasets collected from Bandung, Garut, Subang and Sumedang used as the test cases. Three timesegments (dusk, night and dawn) became the main focus of the analyses and our method successfully extracted following parameters: the rate of sky brightness change at dusk and dawn, the average NSB at night and the intersections which indicate transition time. This method, along with its many possible improvements, enables us to process data more effectively and encourage more observation campaigns to be conducted in the future.
Journal of Physics: Conference Series, 2019
We estimate the mass of three open clusters, NGC 2168, NGC 188, NGC 6819, using kinematics data o... more We estimate the mass of three open clusters, NGC 2168, NGC 188, NGC 6819, using kinematics data of open cluster stars member. Radial velocity data determined from WIYN survey and proper motion determined from Gaia DR2. Using virial theorem and projected-mass estimator method we estimate the mass of star open clusters. Both methods give a reasonable result for all clusters mass. The accuracy of estimated mass affected by some parameters such as membership probability of stars sample, the distance, age, and angular radius of open clusters. We estimate the mass of clusters within a central radius of the cluster. The mass of open clusters using virial theorem is 4056 M⊙ (d < 7 pc) for NGC 2168, 2776 M⊙ (d < 8 pc) for NGC 188, and 4244 M⊙ (d < 1.6 pc) for NGC 6819. Using projected mass estimator we get 5833 M⊙ (d < 7 pc) for NGC 2168, 3326 M⊙ (d < 8pc) for NGC 188, and 3518 M⊙ (d < 1.6pc) for NGC 6819.
Astronomy and Astrophysics Supplement Series, 1999
The photographic observations of 72 visual double stars are presented. The observations were made... more The photographic observations of 72 visual double stars are presented. The observations were made in the years 1992-1997 with the 60-cm double refractor of the Bosscha Observatory at Lembang.
Jurnal Sains Dirgantara, 2010
Yarkovsky effect is a non-gravitational force that works on the object because of anisotropic pho... more Yarkovsky effect is a non-gravitational force that works on the object because of anisotropic photon thermal emission, which brings the momentum to this object. Usually, this effect works in a small meteoroids or asteroids (the diameter about 10 cm to 10 km). In this paper, we try to address the Yarkovsky effect that works on 3362 Khufu (1984 QA) asteroid. Diameter of 3362 Khufu (1984 QA) is 0.7 km, with Bond-albedo is 0.17. Yarkovsky effect will changes the semi major axis of the orbits and then changes the eccentricity. The changing of asteroid's orbital element will bring asteroid into the Earth's orbit. This study shows the changes of the amplitude of semi major axis which is caused by diurnal and seasonal components. The maximum amplitude of each components are 1.3×10-5 m/s and-3.7×10-9 m/s. ABSTRAK Efek Yarkovsky adalah gaya non-gravitasional yang bekerja pada benda yang disebabkan oleh emisi anisotropik foton termal, yang memberi momentum bagi benda tersebut. Efek ini biasanya terjadi pada meteoroid atau asteroid berukuran kecil (dengan diameter 10 cm sampai 10 km). Tulisan ini mencoba meninjau efek Yarkovsky tersebut bagi asteroid 3362 Khufu (1984 QA) yang berdiameter 0.7 km, serta Bond-albedo 0.17. Efek Yarkovsky menyebabkan keubahan pada setengah sumbu panjang orbit, akibatnya eksentrisitas orbit juga berubah. Terjadinya perubahan pada elemen orbit memberikan peluang asteroid tersebut bergerak mendekati Bumi. Telaah ini menunjukkan amplitudo keubahan setengah sumbu panjang orbit terhadap waktu akibat komponen harian dan musiman, masing-masing maksimal adalah 1.3×10-5 m/detik dan-3.7×10-9 m/detik.
Indonesian Journal of Physics, 2019
The orbital dynamic of small objects is an n-body problem that can not be solve by analitically, ... more The orbital dynamic of small objects is an n-body problem that can not be solve by analitically, it is needed to use numerical integration to find the solution instead. This work is about orbital dynamic of asteroid 1566 Icarus under Classical Newtonian gravitation and if thermal effect (Yarkovsky effect) is included. Yarkovsky Effect is a thermal radiation force resulted from time span of small rotating objects to receive heat from the Sun and then re-radiates it. The Yarkovsky Effect is working optimum for objects with diameter from 10 cm up to 10 km, and now is implemented to Asteroid 1566 Icarus with diameter 1.3 km which are member of Apollo and Earth crosser object. This Asteroid is called Earth crosser due to its orbit is crossing Earth’s orbit. With semi major axis a 1.078 au and eccentricity e 0.827, asteroid 1566 Icarus has perihelion distance q = 0.18674 au or less than semi major axis of Mercury. Due to that reason, Yarkovsky effect was considered to be applied on th...
Publications of The Korean Astronomical Society, 2015
In our previous work, we investigated the orbital dynamics of Asteroid 1934 CT (or 1989 AC or 417... more In our previous work, we investigated the orbital dynamics of Asteroid 1934 CT (or 1989 AC or 4179 Toutatis) from epoch 2012-Jul-24 (JDE2456132.5) using the Mercury program package. Asteroid 4179 Toutatis has an Earth and Mars crossing orbit with semimajor axis a = 2.5292 AU and eccentricity e = 0.6294, and therefore the perihelion distance is q = 0.9373 AU and the aphelion distance is Q = 4.1211 AU. After more than 300,000 years, asteroid 4179 Toutatis will escape from the Solar System, but during this time, it will have close-encounters with other planets from Venus to Uranus. As a continuation of this project, we investigated its energy changes in each close encounter. We also determine the energy of this asteroid when it escapes from the Solar System. The result is that during its orbital evolution, the energy of this asteroid changes and gives us negative, zero and positive values.
38Th Cospar Scientific Assembly, 2010
1566 Icarus is an asteroid with special orbital elements; high eccentricity (e = 0.8269), high in... more 1566 Icarus is an asteroid with special orbital elements; high eccentricity (e = 0.8269), high incli-nation (i = 22o .8368), small semimajor-axis (a = 1.0778 AU), argument of perihelion (31o .3393), longitude of ascending node (88o .0474), and mean anomaly (M = 85o .8306) at epoch 2455200.5 JD or January 4, 2010. In this paper, we would like to trace the orbital evolution of 1566 Icarus for 200,000 years, from 100,000 BC until 100,000 AD. The gravitational influence of the eight planets was included in the integrations, which were all carried out using the hybrid inte-grator within the Mercury 6 (Chambers, 1999) software package. From this, we try to predict the behavior of its orbital element by making 243 (35 ) clones of 1566 Icarus. The clones are made by repeated permutation of nominal, nominal+1sigma, nominal-1sigma with the orbital elements: semi-major axis, eccentricity, orbital inclination, longitude of ascending node, and argument of perihelion. From this cloning, we see that the orbital evolution of 1566 Icarus will be stable for 200,000 years, but with small variation in semi-major axis (a).
The most interesting of Asteroid's orbit is the stability of their orbit after long time inte... more The most interesting of Asteroid's orbit is the stability of their orbit after long time integration. If their orbits are not stable they will come into Mars's orbit, or will throw out to Jupiter's orbit. We simulate the orbit of these asteroids using Runge Kutta methods, because the error in the energy, the semi-major axis, and the eccentricity of the asteroid's orbit are linear. In this paper, we would like to try to test seven asteroids which have special position in the Solar system, i.e. Toutatis with semi major axis = 2.51 AU, this is the first Kirkwood Gap; Gaspra with a semi major axis 3.85 AU, the second Kirkwood Gap; Eros, which orbit cuts through Mars's orbit, Icarus with the largest eccentricity among all asteroids, Hektor with position in L4, and Patroclus in L5, and Ceres, the biggest asteroid. To see how stable the program is, we simulate the orbits of Sun, Mercury, Venus, Earth, Mars, while neglecting Jupiter. After that, we would like to see the ...
We present the results of photographic observations of 399 visual double stars of the Hipparcos I... more We present the results of photographic observations of 399 visual double stars of the Hipparcos Input Catalogue (HIC), observed in the years 1980 and 1990-1991 with the 60-cm double-refractor of the Bosscha Observatory at Lembang, Java. (1 data file).
1566 Icarus is an asteroid with special orbital elements; high eccentricity (e = 0.8269), high in... more 1566 Icarus is an asteroid with special orbital elements; high eccentricity (e = 0.8269), high incli-nation (i = 22o .8368), small semimajor-axis (a = 1.0778 AU), argument of perihelion (31o .3393), longitude of ascending node (88o .0474), and mean anomaly (M = 85o .8306) at epoch 2455200.5 JD or January 4, 2010. In this paper, we would like to trace the orbital evolution of 1566 Icarus for 200,000 years, from 100,000 BC until 100,000 AD. The gravitational influence of the eight planets was included in the integrations, which were all carried out using the hybrid inte-grator within the Mercury 6 (Chambers, 1999) software package. From this, we try to predict the behavior of its orbital element by making 243 (35 ) clones of 1566 Icarus. The clones are made by repeated permutation of nominal, nominal+1sigma, nominal-1sigma with the orbital elements: semi-major axis, eccentricity, orbital inclination, longitude of ascending node, and argument of perihelion. From this cloning, we see th...
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Papers by Endang Soegiartini