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The detection of fireballs streaks in astronomical imagery can be carried out by a variety of methods. The Desert Fireball Network uses a network of cameras to track and triangulate incoming fireballs to recover meteorites with orbits and to build a fireball orbital dataset. Fireball detection is done on-board camera, but due to the design constraints imposed by remote deployment, the cameras are limited in processing power and time. We describe the processing software used for fireball detection under these constrained circumstances. Two different approaches were compared: (1) A single-layer neural network with 10 hidden units that were trained using manually selected fireballs and (2) a more traditional computational approach based on cascading steps of increasing complexity, whereby computationally simple filters are used to discard uninteresting portions of the images, allowing for more computationally expensive analysis of the remainder. Both approaches allowed a full night’s worth of data (over a thousand 36-megapixel images) to be processed each day using a low-power single-board computer. We distinguish between large (likely meteorite-dropping) fireballs and smaller fainter ones (typical ‘shooting stars’). Traditional processing and neural network algorithms both performed well on large fireballs within an approximately 30 000-image dataset, with a true positive detection rate of 96% and 100%, respectively, but the neural network was significantly more successful at smaller fireballs, with rates of 67% and 82%, respectively. However, this improved success came at a cost of significantly more false positives for the neural network results, and additionally the neural network does not produce precise fireball coordinates within an image (as it classifies). Simple consideration of the network geometry indicates that overall detection rate for triangulated large fireballs is calculated to be better than 99.7% and 99.9%, by ensuring that there are multiple double-station opportunities to detect any one fireball. As such, both algorithms are considered sufficient for meteor-dropping fireball event detection, with some consideration of the acceptable number of false positives compared to sensitivity.
Radiative transfer is essential for obtaining information from the spectra of astrophysical objects. This volume provides an overview of the physical and mathematical background of radiative transfer, and its applications to stellar and planetary atmospheres. It covers the phenomenology and physics of early-type and late-type stars, as well as ultra-cool dwarf stars and extrasolar planets. Importantly, it provides a bridge between classical radiative transfer and stellar atmosphere modelling and novel approaches, from both theoretical and computational standpoints. With new fields of application and a dramatic improvement in both observational and computational facilities, it also discusses the future outlook for the field. Chapters are written by eminent researchers from across the astronomical disciplines where radiative transfer is employed. Using the most recent observations, this is a go-to resource for graduate students and researchers in astrophysics.
The Murchison Widefield Array (MWA) is an open access telescope dedicated to studying the low-frequency (80–300 MHz) southern sky. Since beginning operations in mid-2013, the MWA has opened a new observational window in the southern hemisphere enabling many science areas. The driving science objectives of the original design were to observe 21 cm radiation from the Epoch of Reionisation (EoR), explore the radio time domain, perform Galactic and extragalactic surveys, and monitor solar, heliospheric, and ionospheric phenomena. All together $60+$ programs recorded 20 000 h producing 146 papers to date. In 2016, the telescope underwent a major upgrade resulting in alternating compact and extended configurations. Other upgrades, including digital back-ends and a rapid-response triggering system, have been developed since the original array was commissioned. In this paper, we review the major results from the prior operation of the MWA and then discuss the new science paths enabled by the improved capabilities. We group these science opportunities by the four original science themes but also include ideas for directions outside these categories.
Lectures on Astrophysics provides an account of classic and contemporary aspects of astrophysics, with an emphasis on analytic calculations and physical understanding. It introduces fundamental topics in astrophysics, including the properties of single and binary stars, the phenomena associated with interstellar matter, and the structure of galaxies. Nobel Laureate Steven Weinberg combines exceptional physical insight with his gift for clear exposition to cover exciting recent developments and new results. Emphasizing theoretical results, and explaining their derivation and application, this book provides an invaluable resource for physics and astronomy students and researchers.
We provide our first experience of Astronomy training as an in-service training of teachers of Science in Primary schools, and teachers of Geography, Physics and Mathematics in Secondary Schools necessitated due to lack of Astronomy specific training in their teacher training programs. The hands-on training was conducted in collaboration with the IAU Commission 46 Working Group program of Network of Astronomy Schools Education (NASE). Experiences from both face to face and virtual sessions conducted during the Covid19 period and in preparation of a major African solar eclipse, are discussed.
In this contribution I will briefly introduce the concept and objectives of the Open Universe Initiative, as well as describe the first steps of its implementation by Brazil, in conjunction with the United Nations Office for Outer Space Affairs (UNOOSA), aiming to encourage new interested parties to join the Initiative.
We propose a set of modern and stimulating activities related to the teaching of Astronomy orientated to high school or university students using smartphones. The activities are: a) the experimental simulation of asteroid light curves including the determination of the period of rotation of asteroids, b) the experimental simulation of exoplanet detection by transit method, c) the experimental simulation of stellar distances using parallax and d) the use of virtual and augmented reality.
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 enthusiasm of teachers who expressed that NASE course could fulfil their needs to teach and instruct students in a very efficient way, it was organized consecutively at Bandar Lampung, Lampung Province in 2018 and 2019 (hosted by Institut Teknologi Sumatera) and in 2020 at Bandung, West Java Province (hosted by Institut Teknologi Bandung). The most recent NASE course on 21–23 August 2020, conducted in on-line mode, was attended by 74 participants, although primarily aimed at 15 School teachers, and was quite successful. The on-line observational activity turned out to be the most impressive session for the participants. We report and review four years of IAU NASE courses in Indonesia, with various documentation and brief analysis of the positive impact to the teachers and instructors attitude in teaching astronomy at secondary level of education.
LLAGN are very important objects for studying as they are found in a large fraction of all massive galaxies. Nevertheless this topic needs more investigation as fraction of LLAGN in all AGN are much more higher than fraction of researches dedicated to LLAGN among all AGN studies. The goal of our work is checking out X-ray properties of LLAGN. For this purpose we created a sample of LLAGN by selecting most prominent LLAGN from literature and analyzed their X-ray spectral properties. As a result, we obtained 12 LLAGN and for 8 of them XMM X-ray observations are available. The spectra from one XMM camera, PN, were fitted with power law + absorption of neutral hydrogen. In the current report we present the previous results of this study. We plan to increase numbers of objects in our future studies.