Browsing by Author "Jopek, Tadeusz J."
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ItemA Main Belt Asteroid: the Most Probable Cause of the Tunguska Event(Societa Astronomica Italiana, 2002) Jopek, Tadeusz J.; Gonczi, Robert; Froeschle, Christiane; Michel, Patric; Longo, Giuseppe; Foschini, LuigiWe studied the available scientific literature on the Tunguska event of 30 June 1908 to select a sample of atmospheric trajectories. Then we calculated a set of parameters from which we obtained 886 orbits. Using the model of Bottke and colleagues on dynamical properties of celestial bodies, we estimated the probabilities of different origins of the Tunguska Cosmic Body (TCB). Event though 6 of 886 orbits can be both asteroidal or cometary, the probability of an asteroidal origins remain s the highest. ItemCurrent status of the IAU MDC Meteor Showers Database(Wydawnictwo Naukowe Uniwersytetu im. Adama Mickiewicza w Poznaniu, 2014) Jopek, Tadeusz J.; Kanuchova, ZuzanaDuring the General Assembly of the IAU in Beijing in 2012, at the business meeting of Commission 22 the list of 31 newly established showers was approved and next o cially accepted by the IAU. As a result, at the end of2013, the list of all established showers contained 95 items. The IAU MDC Working List included 460 meteor showers, among them 95 had pro tempore status. The List of Shower Groups contained 24 complexes, three of them had established status. Jointly, the IAU MDC shower database contained data of 579 showers. ItemMeteoroid streams and their parent bodies(Memorie della Societa Astronomica Italiana, 2011) Jopek, Tadeusz J.Various points concerning meteoroid streams and their parent comets and asteroids are presented. The first connection between meteoroids and comets, among others, were established by G.V. Schiaparelli 150 years ago. The first computer search for meteoroid streams was made by Southworth and Hawkins 50 years ago. Since that time many investigators have been studied the problem of cometary and asteroidal origin of meteoroid streams. Many results have been established. In this study we made the most extensive search for streams and their parent bodies amongst photographic meteoroids, comets and minor planets. We used two D- distance functions and rigorous cluster analysis approach. The well known results have been confirmed -- several major streams and their parents have been identified. Also we found ten associations consisting mainly of the near Earth asteroids. The obtained results do not allow us to make a final conclusions about the genetic reality or the origin of these associations. ItemMeteoroids 2013. Proceedings of the International Conference held at the Adam Mickiewicz University in Poznan, Poland August 26-30, 2013(Wydawnictwo Naukowe Uniwersytetu im. Adama Mickiewicza w Poznaniu, 2014) Jopek, Tadeusz J.; Rietmeijer, Frans J.M.; Watanabe, Junichi; Williams, Iwan P.Proceedings of the International Conference held at the Adam Mickiewicz University in Poznan, Poland August 26-30, 2013 ItemOn the atmospheric dynamics of the Tunguska cosmic body(ESA Publication Division, 2001-11) Foschini, Luigi; Longo, Giuseppe; Jopek, Tadeusz J.; Froeschle, Christiane; Gonczi, Robert; Michel, PatricWe studied the available scientific literature on the Tunguska event of 30 June 1908 to obtain parameter sets of the Tunguska Cosmic Body atmospheric dynamics. We performed a comparative analysis by means of available theoretical models and with the help of interplanetary dynamics, and we excluded unphysical orbits. Our results indicate a very high probability that the TCB was an asteroid. ItemPprównanie dwóch algorytmów identyfikacji strumieni meteoroidowych(Obserwatorium Astronomiczne UAM, 1989) Jopek, Tadeusz J.Porównano dwie metody analizy skupień w próbie 1932 orbit meteoroidów fotograficznych. Wykonane badania ukazują istotne trudności związane z wyszukiwaniem strumieni meteoroidowych. Zastosowano algorytm pojedynczego linkowania oraz iteracyjną metodę Sekaniny. Zidentyfikowano 65 strumieni, połowa z nich nie wymaga dalszych zabiegów. Jednak w pozostałych przypadkach uzyskane tymi metodami rezultaty niekiedy istotnie się różnią. Algorytm Sekaniny działa bardziej selektywnie, daje strumienie o mniejszej liczbie członków, bardziej zwarte. Jednak ze względu na konieczność iterowania, obliczania orbity średniej, rezultaty uzyskane metodą Sekaniny mogą być nieoczekiwane. W tym kontekście algorytm pojedynczego linkowania, jako bezpieczny, jest bardziej godnym polecenia. ItemStudy of meteoroid stream identification methods(Cambridge University Press, 2010) Rudawska, Regina; Jopek, Tadeusz J.We have tested the reliability of various meteoroid streams identification methods. We used a numerically generated set of meteoroid orbits (a stream component and a sporadic background) that were searched for streams using several methods. ItemTV meteor streams searching(Astronomical Institute Slovak Academy of Sciences, Bratislava, 1993) Jopek, Tadeusz J.Using a modified D-criterion (threshold Do=0.2), among 531 TV meteor orbits, 23 streams has been identified. Adout 30% of the orbits belongs to the stream component. Only 3 streams have orbits inclined more than 30deg. Four streams have reciprocal orbits. The major stream Herculids shown to be a complex structure, sensitive on the choice of the D- threshold value. The Taurids complex differs slightly from the photographic one. The theta Piscids stream has very small orbit, the mean semi-major axis equals to 0.79AU. This stream seems to be TV component of the Eccentrides system, but with Do=0.21 the theta Piscids have joined S. Taurids. The TV Orionids appeared in two branches. One of them includes a single orbit which belongs to the eta Aquariids.