Optical observations of NEA 3200 Phaethon (1983 TB) during the 2017 apparition

The near-Earth asteroid 3200 Phaethon (1983 TB) is an attractive object not only from a scientific viewpoint but also because of JAXA's DESTINY+ target. The rotational lightcurve and spin properties were investigated based on the data obtained in the ground-based observation campaign of Phaethon. We aim to refine the lightcurves and shape model of Phaethon using all available lightcurve datasets obtained via optical observation, as well as our time-series observation data from the 2017 apparition. Using eight 1-2-m telescopes and an optical imager, we acquired the optical lightcurves and derived the spin parameters of Phaethon. We applied the lightcurve inversion method and SAGE algorithm to deduce the convex and non-convex shape model and pole orientations. We analysed the optical lightcurve of Phaethon and derived a synodic and a sidereal rotational period of 3.6039 h, with an axis ratio of a/b = 1.07. The ecliptic longitude (lambda) and latitude (beta) of the pole orientation were determined as (308, -52) and (322, -40) via two independent methods. A non-convex model from the SAGE method, which exhibits a concavity feature, is also presented.Comment: 14 pages, 4 figures, 1 figure in Appendix A. Accepted for publication in Astronomy & Astrophysics (A&A

Apophis planetary defense campaign

We describe results of a planetary defense exercise conducted during the close approach to Earth by the near-Earth asteroid (99942) Apophis during 2020 December–2021 March. The planetary defense community has been conducting observational campaigns since 2017 to test the operational readiness of the global planetary defense capabilities. These community-led global exercises were carried out with the support of NASA's Planetary Defense Coordination Office and the International Asteroid Warning Network. The Apophis campaign is the third in our series of planetary defense exercises. The goal of this campaign was to recover, track, and characterize Apophis as a potential impactor to exercise the planetary defense system including observations, hypothetical risk assessment and risk prediction, and hazard communication. Based on the campaign results, we present lessons learned about our ability to observe and model a potential impactor. Data products derived from astrometric observations were available for inclusion in our risk assessment model almost immediately, allowing real-time updates to the impact probability calculation and possible impact locations. An early NEOWISE diameter measurement provided a significant improvement in the uncertainty on the range of hypothetical impact outcomes. The availability of different characterization methods such as photometry, spectroscopy, and radar provided robustness to our ability to assess the potential impact risk

Photometry of the Didymos System across the DART Impact Apparition

On 2022 September 26, the Double Asteroid Redirection Test (DART) spacecraft impacted Dimorphos, the satellite of binary near-Earth asteroid (65803) Didymos. This demonstrated the efficacy of a kinetic impactor for planetary defense by changing the orbital period of Dimorphos by 33 minutes. Measuring the period change relied heavily on a coordinated campaign of lightcurve photometry designed to detect mutual events (occultations and eclipses) as a direct probe of the satellite’s orbital period. A total of 28 telescopes contributed 224 individual lightcurves during the impact apparition from 2022 July to 2023 February. We focus here on decomposable lightcurves, i.e., those from which mutual events could be extracted. We describe our process of lightcurve decomposition and use that to release the full data set for future analysis. We leverage these data to place constraints on the postimpact evolution of ejecta. The measured depths of mutual events relative to models showed that the ejecta became optically thin within the first ∼1 day after impact and then faded with a decay time of about 25 days. The bulk magnitude of the system showed that ejecta no longer contributed measurable brightness enhancement after about 20 days postimpact. This bulk photometric behavior was not well represented by an HG photometric model. An HG 1 G 2 model did fit the data well across a wide range of phase angles. Lastly, we note the presence of an ejecta tail through at least 2023 March. Its persistence implied ongoing escape of ejecta from the system many months after DART impact

Crystallisation of meaning as a technique for forming intercultural communicative competence within the real–virtual dichotomy

The article explores the formation of intercultural communicative competence within the framework of the “real – virtual” dichotomy. The principal instrument of formation is the meaning crystallisation technique based on the material of media discourse as well as computer and art-specific types of discourse. The discourse is viewed as a complex structural and semantic formation, an axiological system that has a definite functional perspective; it represents itself as a domain for realisation of specific values or their facets depending on the situational context, as actualisation of interaction between textual structures and extra-linguistic factors. The discourse is based on the system of concepts relevant for intercultural communication. The concept is a totality of meanings representing an axiological category that is important within the space of a particular discourse. Language is social and pragmatic in its core; therefore, the substantive and semantic aspects of linguistic units are connected with socio-cultural factors, the ways of vision and comprehension of objects. The relevance of research in this sphere is determined by: 1) the growing interest in the problems of dialogue of cultures and intercultural communication; 2) the attention of researchers to the structural and semantic organisation of discursive spheres; 3) the specificity of communication types that have a significant impact on the social worldview; 4) the importance of identification and formation of axiological benchmarks in the society; 5) the features related with extension of the virtual interaction sphere. Crystallisation is principally a process in which interpretation is used to trace the semantic content of words that, in the context of thinking or art, becomes independent of the norm fixed by dictionary definitions. The study of crystallisation processes involves the analysis of concepts in terms of dialogue of cultures. Concepts are verbalised in accordance with the nature and uniqueness of material, spiritual and social culture, in close connection with linguistic and pragmatic components. The research results can be used in courses on foreign language teaching methodology, theory and practice of intercultural communication, discourse theory, stylistics, and interpretation of texts

The changing rotation period of 3200 Phaethon

International audience3200 Phaethon is one of the largest potentially hazardous asteroids. It is also the first asteroid to be discovered in spacecraft images, the parent body of the Geminid meteor stream, and the target of JAXA's upcoming DESTINY+ mission. We have developed a physical model of Phaethon's shape and rotation state, using radar data from Arecibo and Goldstone in 2007 and 2017, stellar occultations from 2019 through 2021, and lightcurves from many apparitions (from 1989 through 2021). Phaethon has a volume-equivalent diameter of about 5.3 kilometers. It is approximately spheroidal with an equatorial ridge, resembling the shapes of 101955 Bennu and 162173 Ryugu. The earliest available lightcurve of Phaethon is from 1989 October 9 (published in Wisniewski et al. 1997). Hanuš et al. (2016) noticed that their shape model's rotation phase differed from that 1989 observation by about 20 minutes. They noted that this may be from Phaethon's rotation period changing due to activity, but they could not say whether this was real or just a timing error in that one lightcurve, since the next lightcurves are from 1994. A model with a constant rotation period provided a good fit to all of the data from 1994 through 2020. However, this model could not adequately fit the lightcurves that were acquired from four different observatories in 2021. There was a difference of about 15 minutes between the predicted and observed rotation phases — clearly greater than what the observations' uncertainties could permit. We initially considered that Phaethon's rotation period may have changed before the 2021 observations, perhaps due to activity when it was near perihelion in December 2020. However, we found that a constant rotational acceleration provides a good fit to all of the data from 1989 through 2021, clearly accounting for the discrepancies seen in 1989 and 2021 while also slightly improving the model's agreement with the data during other apparitions. We find that Phaethon's sidereal rotation period in December 2017 was 3.603944 hours. Its spin rate is increasing at a rate of 2.1×10-6 deg/day2, which corresponds to its rotation period decreasing by about 4 milliseconds per year

The changing rotation period of 3200 Phaethon

International audience3200 Phaethon is one of the largest potentially hazardous asteroids. It is also the first asteroid to be discovered in spacecraft images, the parent body of the Geminid meteor stream, and the target of JAXA's upcoming DESTINY+ mission. We have developed a physical model of Phaethon's shape and rotation state, using radar data from Arecibo and Goldstone in 2007 and 2017, stellar occultations from 2019 through 2021, and lightcurves from many apparitions (from 1989 through 2021). Phaethon has a volume-equivalent diameter of about 5.3 kilometers. It is approximately spheroidal with an equatorial ridge, resembling the shapes of 101955 Bennu and 162173 Ryugu. The earliest available lightcurve of Phaethon is from 1989 October 9 (published in Wisniewski et al. 1997). Hanuš et al. (2016) noticed that their shape model's rotation phase differed from that 1989 observation by about 20 minutes. They noted that this may be from Phaethon's rotation period changing due to activity, but they could not say whether this was real or just a timing error in that one lightcurve, since the next lightcurves are from 1994. A model with a constant rotation period provided a good fit to all of the data from 1994 through 2020. However, this model could not adequately fit the lightcurves that were acquired from four different observatories in 2021. There was a difference of about 15 minutes between the predicted and observed rotation phases — clearly greater than what the observations' uncertainties could permit. We initially considered that Phaethon's rotation period may have changed before the 2021 observations, perhaps due to activity when it was near perihelion in December 2020. However, we found that a constant rotational acceleration provides a good fit to all of the data from 1989 through 2021, clearly accounting for the discrepancies seen in 1989 and 2021 while also slightly improving the model's agreement with the data during other apparitions. We find that Phaethon's sidereal rotation period in December 2017 was 3.603944 hours. Its spin rate is increasing at a rate of 2.1×10-6 deg/day2, which corresponds to its rotation period decreasing by about 4 milliseconds per year

Вплив транспарентності публічних фінансів на рівень корупції в Україні

Корупція в Україні значно перевищує середньоєвропейський рівень, що робить цю проблему однією з ключових перешкод для ефективної реформи соціально-економічних відносин для просування європейських цінностей та забезпечення сталого економічного зростання. На наш погляд, корупцію слід трактувати як складне явище, зміст якого визначається як економічними законами, так і суспільно-політичними процесами. Зважаючи на складність тлумачення корупції, інструменти боротьби з цим явищем можна розділити на дві великі групи. По-перше, прямі заходи репресій, які в основному стосуються сфери діяльності антикорупційних органів: Вищий антикорупційний суд України, Національне антикорупційне бюро, Спеціалізована антикорупційна прокуратура, Національне агентство з питань боротьби з корупцією та Державне бюро розслідувань. По-друге, стратегічні комплексні профілактичні заходи. Ці заходи формують передумови для зміни думки учасників економічних відносин та запроваджують системні гарантії вчинення корупції. Одним із ключових інструментів другої групи є підвищення прозорості функціонування інститутів державних фінансів, а також забезпечення прозорості всіх складових державної економічної політики, опосередкованих рухом фінансових ресурсів. Ця монографія вивчає методологічні основи забезпечення прозорості державних фінансів в Україні; а також методологічні підходи щодо підвищення прозорості функціонування окремих суб'єктів (банківських груп, державних банків, небанківських фінансових посередників) та систем (протидія відмиванню незаконного доходу, кредитної інформації) у цій галузі.Коррупция в Украине значительно превышает среднеевропейский уровень, что делает эту проблему одним из ключевых препятствий для эффективной реформы социально-экономических отношений с целью продвижения европейских ценностей и обеспечения устойчивого экономического роста. На наш взгляд, коррупцию следует интерпретировать как сложное явление, содержание которого определяется как экономическими законами, так и социально-политическими процессами. Учитывая сложность интерпретации коррупции, инструменты борьбы с этим явлением можно разделить на две большие группы. Во-первых, прямые меры репрессий, которые в основном относятся к сфере деятельности антикоррупционных органов: Верховный антикоррупционный суд Украины, Национальное антикоррупционное бюро, Специализированная антикоррупционная прокуратура, Национальное антикоррупционное агентство и Государственное бюро расследований. Во-вторых, стратегические комплексные профилактические меры. Эти меры формируют предпосылки для изменения взглядов участников экономических отношений и вводят системные гарантии для совершения коррупции. Одним из ключевых инструментов второй группы является повышение прозрачности функционирования институтов государственных финансов, а также обеспечение прозрачности всех компонентов государственной экономической политики, которые опосредуются движением финансовых ресурсов. В этой монографии рассматриваются методологические основы обеспечения прозрачности государственных финансов в Украине; а также методологические подходы к повышению прозрачности функционирования отдельных субъектов (банковских групп, государственных банков, небанковских финансовых посредников) и систем (противодействие отмыванию незаконных доходов, кредитной информации) в этой области.Corruption in Ukraine substantially exceeds the European average level, which makes this problem one of the key obstacles for effective reform of socio-economic relations to promote European values and ensure sustainable economic growth. In our view, corruption should be interpreted as a complex phenomenon, the content of which is determined by both economic laws and socio-political processes. Given the complexity of the interpretation of corruption, the tools to combat this phenomenon can be divided into two large groups. First, direct measures of repression, which mainly relate to the sphere of activity of anti-corruption bodies: The Supreme Anticorruption Court of Ukraine, the National Anti-Corruption Bureau, the Specialized Anti-corruption Prosecutor's Office, the National Anti-Corruption Agency and the State Bureau of Investigation. Second, strategic integrated preventive measures. These measures form the prerequisites for changing the minds of participants in economic relations and introduce systemic safeguards for committing corruption. One of the key instruments of the second group is to increase the transparency of the functioning of public finance institutions, as well as to ensure the transparency of all components of state economic policy, which are mediated by the movement of financial resources. This monograph examines the methodological foundations for ensuring transparency of public finance in Ukraine; as well as methodological approaches to increase the transparency of the functioning of individual entities (banking groups, state-owned banks, non-bank financial intermediaries) and systems (counteraction to the laundering of illegal income, credit information) in this field

Вплив транспарентності публічних фінансів на рівень корупції в Україні

Корупція в Україні значно перевищує середньоєвропейський рівень, що робить цю проблему однією з ключових перешкод для ефективної реформи соціально-економічних відносин для просування європейських цінностей та забезпечення сталого економічного зростання. На наш погляд, корупцію слід трактувати як складне явище, зміст якого визначається як економічними законами, так і суспільно-політичними процесами. Зважаючи на складність тлумачення корупції, інструменти боротьби з цим явищем можна розділити на дві великі групи. По-перше, прямі заходи репресій, які в основному стосуються сфери діяльності антикорупційних органів: Вищий антикорупційний суд України, Національне антикорупційне бюро, Спеціалізована антикорупційна прокуратура, Національне агентство з питань боротьби з корупцією та Державне бюро розслідувань. По-друге, стратегічні комплексні профілактичні заходи. Ці заходи формують передумови для зміни думки учасників економічних відносин та запроваджують системні гарантії вчинення корупції. Одним із ключових інструментів другої групи є підвищення прозорості функціонування інститутів державних фінансів, а також забезпечення прозорості всіх складових державної економічної політики, опосередкованих рухом фінансових ресурсів. Ця монографія вивчає методологічні основи забезпечення прозорості державних фінансів в Україні; а також методологічні підходи щодо підвищення прозорості функціонування окремих суб'єктів (банківських груп, державних банків, небанківських фінансових посередників) та систем (протидія відмиванню незаконного доходу, кредитної інформації) у цій галузі.Коррупция в Украине значительно превышает среднеевропейский уровень, что делает эту проблему одним из ключевых препятствий для эффективной реформы социально-экономических отношений с целью продвижения европейских ценностей и обеспечения устойчивого экономического роста. На наш взгляд, коррупцию следует интерпретировать как сложное явление, содержание которого определяется как экономическими законами, так и социально-политическими процессами. Учитывая сложность интерпретации коррупции, инструменты борьбы с этим явлением можно разделить на две большие группы. Во-первых, прямые меры репрессий, которые в основном относятся к сфере деятельности антикоррупционных органов: Верховный антикоррупционный суд Украины, Национальное антикоррупционное бюро, Специализированная антикоррупционная прокуратура, Национальное антикоррупционное агентство и Государственное бюро расследований. Во-вторых, стратегические комплексные профилактические меры. Эти меры формируют предпосылки для изменения взглядов участников экономических отношений и вводят системные гарантии для совершения коррупции. Одним из ключевых инструментов второй группы является повышение прозрачности функционирования институтов государственных финансов, а также обеспечение прозрачности всех компонентов государственной экономической политики, которые опосредуются движением финансовых ресурсов. В этой монографии рассматриваются методологические основы обеспечения прозрачности государственных финансов в Украине; а также методологические подходы к повышению прозрачности функционирования отдельных субъектов (банковских групп, государственных банков, небанковских финансовых посредников) и систем (противодействие отмыванию незаконных доходов, кредитной информации) в этой области.Corruption in Ukraine substantially exceeds the European average level, which makes this problem one of the key obstacles for effective reform of socio-economic relations to promote European values and ensure sustainable economic growth. In our view, corruption should be interpreted as a complex phenomenon, the content of which is determined by both economic laws and socio-political processes. Given the complexity of the interpretation of corruption, the tools to combat this phenomenon can be divided into two large groups. First, direct measures of repression, which mainly relate to the sphere of activity of anti-corruption bodies: The Supreme Anticorruption Court of Ukraine, the National Anti-Corruption Bureau, the Specialized Anti-corruption Prosecutor's Office, the National Anti-Corruption Agency and the State Bureau of Investigation. Second, strategic integrated preventive measures. These measures form the prerequisites for changing the minds of participants in economic relations and introduce systemic safeguards for committing corruption. One of the key instruments of the second group is to increase the transparency of the functioning of public finance institutions, as well as to ensure the transparency of all components of state economic policy, which are mediated by the movement of financial resources. This monograph examines the methodological foundations for ensuring transparency of public finance in Ukraine; as well as methodological approaches to increase the transparency of the functioning of individual entities (banking groups, state-owned banks, non-bank financial intermediaries) and systems (counteraction to the laundering of illegal income, credit information) in this field

Repetitive patterns in rapid optical variations in the nearby black-hole binary V404 Cygni

ブラックホール近傍から出る規則的なパターンを持つ光の変動を可視光で初めて捉えることに成功 -ブラックホールの「またたき」を直接目で観測できる機会に期待-. 京都大学プレスリリース. 2016-01-07.How black holes accrete surrounding matter is a fundamental yet unsolved question in astrophysics. It is generally believed that matter is absorbed into black holes via accretion disks, the state of which depends primarily on the mass-accretion rate. When this rate approaches the critical rate (the Eddington limit), thermal instability is supposed to occur in the inner disk, causing repetitive patterns of large-amplitude X-ray variability (oscillations) on timescales of minutes to hours. In fact, such oscillations have been observed only in sources with a high mass-accretion rate, such as GRS 1915+105 (refs 2, 3). These large-amplitude, relatively slow timescale, phenomena are thought to have physical origins distinct from those of X-ray or optical variations with small amplitudes and fast timescales (less than about 10 seconds) often observed in other black-hole binaries--for example, XTE J1118+480 (ref. 4) and GX 339−4 (ref. 5). Here we report an extensive multi-colour optical photometric data set of V404 Cygni, an X-ray transient source containing a black hole of nine solar masses (and a companion star) at a distance of 2.4 kiloparsecs (ref. 8). Our data show that optical oscillations on timescales of 100 seconds to 2.5 hours can occur at mass-accretion rates more than ten times lower than previously thought. This suggests that the accretion rate is not the critical parameter for inducing inner-disk instabilities. Instead, we propose that a long orbital period is a key condition for these large-amplitude oscillations, because the outer part of the large disk in binaries with long orbital periods will have surface densities too low to maintain sustained mass accretion to the inner part of the disk. The lack of sustained accretion--not the actual rate--would then be the critical factor causing large-amplitude oscillations in long-period systems