Program of the 34 International Meteor Conference
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The Leonid Meteor Shower: Historical Visual Observations
Icarus 138, 287–308 (1999) Article ID icar.1998.6074, available online at http://www.idealibrary.com on The Leonid Meteor Shower: Historical Visual Observations P. Brown Department of Physics and Astronomy, University of Western Ontario, London, Ontario, N6A 3K7, Canada E-mail: [email protected] Received July 20, 1998; revised December 10, 1998 of past showers, independent of the many secondary accounts The original visual accounts of the Leonids from 1799 to 1997 which appear in the literature, in an effort to better understand are examined and the times and magnitude of peak activity are the stream’s past activity, its formation, and as a way to predict established for 32 Leonid returns during this two-century interval. what may happen in the years from 1999 onwards. In addition, Previous secondary accounts of many of these returns are shown this revised set of historical Leonid data provides a set of obser- to differ from the information contained in the original accounts vations reduced in a common manner, which any model of the due to misinterpretations, typographical errors, and unsupported stream must be able to explain and to which others can easily assumptions. The strongest Leonid storms are shown to follow a examine and apply their own corrections. Gaussian activity profile and to occur after the perihelion passage In this work, we examine in detail available original records and nodal longitude of 55P/Tempel–Tuttle. The relationship be- tween the Gaussian width of the strongest returns and their peak of the Leonids for modern returns of the shower (here defined activity is established, and the particle density/stream width rela- to be post-1799). -
Meteor Shower Detection with Density-Based Clustering
Meteor Shower Detection with Density-Based Clustering Glenn Sugar1*, Althea Moorhead2, Peter Brown3, and William Cooke2 1Department of Aeronautics and Astronautics, Stanford University, Stanford, CA 94305 2NASA Meteoroid Environment Office, Marshall Space Flight Center, Huntsville, AL, 35812 3Department of Physics and Astronomy, The University of Western Ontario, London N6A3K7, Canada *Corresponding author, E-mail: [email protected] Abstract We present a new method to detect meteor showers using the Density-Based Spatial Clustering of Applications with Noise algorithm (DBSCAN; Ester et al. 1996). DBSCAN is a modern cluster detection algorithm that is well suited to the problem of extracting meteor showers from all-sky camera data because of its ability to efficiently extract clusters of different shapes and sizes from large datasets. We apply this shower detection algorithm on a dataset that contains 25,885 meteor trajectories and orbits obtained from the NASA All-Sky Fireball Network and the Southern Ontario Meteor Network (SOMN). Using a distance metric based on solar longitude, geocentric velocity, and Sun-centered ecliptic radiant, we find 25 strong cluster detections and 6 weak detections in the data, all of which are good matches to known showers. We include measurement errors in our analysis to quantify the reliability of cluster occurrence and the probability that each meteor belongs to a given cluster. We validate our method through false positive/negative analysis and with a comparison to an established shower detection algorithm. 1. Introduction A meteor shower and its stream is implicitly defined to be a group of meteoroids moving in similar orbits sharing a common parentage. -
7 X 11 Long.P65
Cambridge University Press 978-0-521-85349-1 - Meteor Showers and their Parent Comets Peter Jenniskens Index More information Index a – semimajor axis 58 twin shower 440 A – albedo 111, 586 fragmentation index 444 A1 – radial nongravitational force 15 meteoroid density 444 A2 – transverse, in plane, nongravitational force 15 potential parent bodies 448–453 A3 – transverse, out of plane, nongravitational a-Centaurids 347–348 force 15 1980 outburst 348 A2 – effect 239 a-Circinids (1977) 198 ablation 595 predictions 617 ablation coefficient 595 a-Lyncids (1971) 198 carbonaceous chondrite 521 predictions 617 cometary matter 521 a-Monocerotids 183 ordinary chondrite 521 1925 outburst 183 absolute magnitude 592 1935 outburst 183 accretion 86 1985 outburst 183 hierarchical 86 1995 peak rate 188 activity comets, decrease with distance from Sun 1995 activity profile 188 Halley-type comets 100 activity 186 Jupiter-family comets 100 w 186 activity curve meteor shower 236, 567 dust trail width 188 air density at meteor layer 43 lack of sodium 190 airborne astronomy 161 meteoroid density 190 1899 Leonids 161 orbital period 188 1933 Leonids 162 predictions 617 1946 Draconids 165 upper mass cut-off 188 1972 Draconids 167 a-Pyxidids (1979) 199 1976 Quadrantids 167 predictions 617 1998 Leonids 221–227 a-Scorpiids 511 1999 Leonids 233–236 a-Virginids 503 2000 Leonids 240 particle density 503 2001 Leonids 244 amorphous water ice 22 2002 Leonids 248 Andromedids 153–155, 380–384 airglow 45 1872 storm 380–384 albedo (A) 16, 586 1885 storm 380–384 comet 16 1899 -
Smithsonian Contributions Astrophysics
SMITHSONIAN CONTRIBUTIONS to ASTROPHYSICS Number 14 Discrete Levels off Beginning Height off Meteors in Streams By A. F. Cook Number 15 Yet Another Stream Search Among 2401 Photographic Meteors By A. F. Cook, B.-A. Lindblad, B. G. Marsden, R. E. McCrosky, and A. Posen Smithsonian Institution Astrophysical Observatory Smithsonian Institution Press SMITHSONIAN CONTRIBUTIONS TO ASTROPHYSICS NUMBER 14 A. F. cook Discrete Levels of Beginning Height of Meteors in Streams SMITHSONIAN INSTITUTION PRESS CITY OF WASHINGTON 1973 Publications of the Smithsonian Institution Astrophysical Observatory This series, Smithsonian Contributions to Astrophysics, was inaugurated in 1956 to provide a proper communication for the results of research conducted at the Astrophysical Observatory of the Smithsonian Institution. Its purpose is the "increase and diffusion of knowledge" in the field of astrophysics, with particular emphasis on problems of the sun, the earth, and the solar system. Its pages are open to a limited number of papers by other investigators with whom we have common interests. Another series, Annals of the Astrophysical Observatory, was started in 1900 by the Observa- tory's first director, Samuel P. Langley, and was published about every ten years. These quarto volumes, some of which are still available, record the history of the Observatory's researches and activities. The last volume (vol. 7) appeared in 1954. Many technical papers and volumes emanating from the Astrophysical Observatory have appeared in the Smithsonian Miscellaneous Collections. Among these are Smithsonian Physical Tables, Smithsonian Meteorological Tables, and World Weather Records. Additional information concerning these publications can be obtained from the Smithsonian Institution Press, Smithsonian Institution, Washington, D.C. -
Events: No General Meeting in April
The monthly newsletter of the Temecula Valley Astronomers Apr 2020 Events: No General Meeting in April. Until we can resume our monthly meetings, you can still interact with your astronomy associates on Facebook or by posting a message to our mailing list. General information: Subscription to the TVA is included in the annual $25 membership (regular members) donation ($9 student; $35 family). President: Mark Baker 951-691-0101 WHAT’S INSIDE THIS MONTH: <[email protected]> Vice President: Sam Pitts <[email protected]> Cosmic Comments Past President: John Garrett <[email protected]> by President Mark Baker Treasurer: Curtis Croulet <[email protected]> Looking Up Redux Secretary: Deborah Baker <[email protected]> Club Librarian: Vacant compiled by Clark Williams Facebook: Tim Deardorff <[email protected]> Darkness – Part III Star Party Coordinator and Outreach: Deborah Baker by Mark DiVecchio <[email protected]> Hubble at 30: Three Decades of Cosmic Discovery Address renewals or other correspondence to: Temecula Valley Astronomers by David Prosper PO Box 1292 Murrieta, CA 92564 Send newsletter submissions to Mark DiVecchio th <[email protected]> by the 20 of the month for Members’ Mailing List: the next month's issue. [email protected] Website: http://www.temeculavalleyastronomers.com/ Like us on Facebook Page 1 of 18 The monthly newsletter of the Temecula Valley Astronomers Apr 2020 Cosmic Comments by President Mark Baker One of the things commonly overlooked about Space related Missions is time, and of course, timing…!!! Many programs take a decade just to get them in place and off the ground, and many can take twice that long…just look at the James Webb Telescope!!! So there’s the “time” aspect of such endeavors…what about timing?? I mentioned last month that July is looking like a busy month for Martian Missions… here’s a refresher: 1) The NASA Mars 2020 rover Perseverance and its helicopter drone companion (aka Lone Ranger and Tonto, as I called them) is still on schedule. -
Backyard Astronomy Santa Fe Public Library
Backyard Astronomy Santa Fe Public Library Photo Credit: NASA, A Mess of Stars,08-10-2015 1. What will you need? 2. What am I looking at? 3. What you can See a. August 2020 b. September 2020 c. October 2020 4. Star Stories 5. Activities a. Tracking the Sunset/Sunrise b. Moon Watching c. Tracking the International Space Station d. Constellation Discovery 6. What to Read Backyard Astronomy Santa Fe Public Library What will you need? The most important things you will need are your curiosity, your naked eyes, and the ability to observe. You do not need fancy telescopes to begin enjoying the wonders of our amazing night skies. Here in Northern New Mexico, we are blessed with the ability to step out of our homes, look up, and see the Milky Way displayed above us without too much obstruction. Photo Credit: NASA, A Glimpse of the Milky Way, 12-13-2005 While the following Items can help you to begin exploring the wonders of the Universe, they are not required. These items include: 1. Binoculars 2. Telescope (a small inexpensive one is fine) 3. Star Chart Planisphere 4. Free Astronomy Apps for both iPhones and Androids There are several really good free apps that help you identify, locate, and track celestial objects. One that I use is Star Walk 2 but there are other good apps available. Backyard Astronomy Santa Fe Public Library What am I looking at? When you look up at night, what do you see? Probably more than you think! Below is a list of the Celestial Items you can see. -
For the Love of Meteors by Cathy L
For the Love of Meteors by Cathy L. Hall, Kingston Centre ([email protected]) November 17/18, 1999 igh in the mountains above Malaga, Spain, far above the Hbeaches of the Costa Del Sol, eight meteor observers from several continents were treated to a memorable display of Leonid meteors. The group included Jürgen Rendtel, Manuela Trenn, Rainer Arlt, Sirko Molau, and Ralf Koschack from Germany, Robert Lunsford from California, and Pierre Martin and myself from Canada. Further east, another group of Canadians, Les MacDonald, Joe Dafoe, and Gwen Hoover, observed from northern Cyprus. Over the course of more than five hours that night, those of us in southern Spain recorded an incredible number of meteors, with most of us seeing between 1,000 and 2,000 Leonids. The group in Cyprus was Left to right: Robert Lundsford of San Diego, California (IMO Secretary-General and AMS Visual hindered by cloud, but was still delighted Program Co-ordinator), the author, Pierre Martin of Orleans, Ontario (Ottawa Centre’s Meteor Co- with the Leonids’ performance. ordinator), and Sirko Molau of Aachen, Germany (IMO Video Commission Director). The photo was It was a beautiful display in the taken at the Berlin Observatory prior to flying to southern Spain to observe the Leonids. mountains over Malaga. The meteors and comets I have seen over the years have mountains as the Leonids started to fall. like soft notes on a flute. There would be always been very personal things. I like The earliest Leonid meteors were a a brief lull, followed by another tiny burst to enjoy them alone, if possible. -
3D/Biela and the Andromedids: Fragmenting Versus Sublimating Comets P
The Astronomical Journal, 134:1037 Y 1045, 2007 September # 2007. The American Astronomical Society. All rights reserved. Printed in U.S.A. 3D/BIELA AND THE ANDROMEDIDS: FRAGMENTING VERSUS SUBLIMATING COMETS P. Jenniskens1 and J. Vaubaillon2 Received 2007 January 3; accepted 2007 April 22 ABSTRACT Comet 3D/Biela broke up in 1842/1843 and continued to disintegrate in the returns of 1846 and 1852. When meteor storms were observed in November of 1872 and 1885, it was surmised that those showers were the debris from that breakup. This could have come from one of two sources: (1) the initial separation of fragments near aphelion or (2) the continued disintegration of the fragments afterward. Alternatively, the meteoroids could simply have come from water vapor drag when the fragments approached perihelion (option 3). We investigated the source of the Andromedid storms by calculating the dynamical evolution of dust ejected in a normal manner by water vapor drag in the returns from 1703 to 1866, assuming that the comet would have remained similarly active over each return. In addition, we simulated the isotropic ejection of dust during the initial fragmentation event at aphelion in December of 1842. We conclude that option 2 is the most likely source of meteoroids encountered during the 1872 and 1885 storms, but this accounts for only a relatively small amount of mass lost in a typical comet breakup. Key words: comets: individual (3D/Biela) — meteors, meteoroids — minor planets, asteroids 1. INTRODUCTION 2. THE COMET AND ITS SHOWER Ever since Whipple (1951) showed that water vapor can ac- 2.1. -
Radio Echo Observations of Meteors in the Southern Hemisphere
RADIO ECHO OBSERVATIONS OF METEORS IN THE SOUTHERN HEMISPHERE By A. A. WEISS* [Manuscript received September 20, 1954] Summary The results of a radio survey of meteor activity at Adelaide are presented. The radiants and activities of six major meteor showers (Geminids, day-time Arietids, ~-Perseids, a-Aquarids, Corona Australids, Orionids) have been measured by methods which are described, and the mass distributions in three of these showers are discussed. Seasonal and diurnal variations in the background activity of sporadic meteors are examined in relation to the radiation patterns of the aerial systems_ Height distribut.ions for meteors of three showers (Geminids, day-time Arietids, ~-Perseids) are given. Diurnal variations in the height distribution of sporadic meteors do not conform to those expected from the motion of the apex of the Earth's way. I. INTRODUCTION The successful application, at the Jodrell Bank Experimental Station of the University of Manchester, of radio echo techniques to the continuous monitoring of meteor activity in the northern hemisphere, prompted the initiation ()f a complementary survey in the southern hemisphere. Up to the time of (lommencement of this survey lists of southern hemisphere visual observations had been published by McIntosh and by Hoffmeister, and McIntosh (1935) had compiled" An Index to Southern Meteor Showers" which lists 320 radiants visible at mid-southern latitudes. These visual observations have since been supplemented by radio echo observations on the a-Aquarid shower by Hawkins and Almond (1952) and by Lindblad (1952). Although it is certain that all major southern night-time showers have been detected by the visual workers, the cover in the months September to March is not altogether satisfactory (McIntosh 1935). -
Meteors Ebook, Epub
METEORS PDF, EPUB, EBOOK Melissa Stewart | 32 pages | 01 Jun 2015 | National Geographic Kids | 9781426319433 | English | London, United Kingdom Meteors PDF Book These particles might affect climate, both by scattering electromagnetic radiation and by catalyzing chemical reactions in the upper atmosphere. This year, with a 60 percent illuminated moon rising near pm local summer time, one could easily dismiss the probably of seeing anything extraordinary from this source. Oxford Dictionary of Astronomy. Early Earth experienced many large meteor impacts that caused extensive destruction. At this time, the moon is located near the sun and is invisible at night. Stony meteoroids without these features are called " achondrites ", which are typically formed from extraterrestrial igneous activity; they contain little or no extraterrestrial iron. Meteorites are bits of the solar system that have fallen to the Earth. What's Up - January More than 1, people were injured in the blast, mostly due to broken glass. They have three main classifications: iron, stone, and stony-iron. If a meteor survives its transit of the atmosphere to come to rest on the Earth's surface, the resulting object is called a meteorite. Photographing a meteor shower can be an exercise in patience, but with these tips — and some good fortune — you might be rewarded with a great photo. Meteor radars can measure atmospheric density and winds by measuring the decay rate and Doppler shift of a meteor trail. When a meteor comes hurtling toward Earth, the high-pressure air in front of it seeps into its pores Meteorite Impacts in History. Another rare phenomenon is a meteor procession , where the meteor breaks up into several fireballs traveling nearly parallel to the surface of Earth. -
Spectra and Physical Properties of Taurid Meteoroids
Spectra and physical properties of Taurid meteoroids Pavol Matloviˇca, Juraj T´otha, Regina Rudawskab, Leonard Kornoˇsa aFaculty of Mathematics, Physics and Informatics, Comenius University, Bratislava, Slovakia bESA European Space Research and Technology Centre, Noordwijk, Netherlands Abstract Taurids are an extensive stream of particles produced by comet 2P/Encke, which can be observed mainly in October and November as a series of me- teor showers rich in bright fireballs. Several near-Earth asteroids have also been linked with the meteoroid complex, and recently the orbits of two car- bonaceous meteorites were proposed to be related to the stream, raising interesting questions about the origin of the complex and the composition of 2P/Encke. Our aim is to investigate the nature and diversity of Taurid mete- oroids by studying their spectral, orbital, and physical properties determined from video meteor observations. Here we analyze 33 Taurid meteor spectra captured during the predicted outburst in November 2015 by stations in Slo- vakia and Chile, including 14 multi-station observations for which the orbital elements, material strength parameters, dynamic pressures, and mineralog- ical densities were determined. It was found that while orbits of the 2015 Taurids show similarities with several associated asteroids, the obtained spec- tral and physical characteristics point towards cometary origin with highly heterogeneous content. Observed spectra exhibited large dispersion of iron content and significant Na intensity in all cases. The determined material strengths are typically cometary in the KB classification, while PE criterion is on average close to values characteristic for carbonaceous bodies. The studied meteoroids were found to break up under low dynamic pressures of 0.02 - 0.10 MPa, and were characterized by low mineralogical densities of 1.3 arXiv:1704.06482v1 [astro-ph.EP] 21 Apr 2017 - 2.5 g cm-3. -
96P/Machholz
The age of the meteoroid complex of comet 96P/Machholz Abedin Y. Abedin Paul A. Wiegert Petr Pokorny Peter G. Brown Introduction • Associated with 8 meteor showers - QUA, ARI, SDA, NDA, KVE, Carinids, 훂-Cetids, Ursids. (Babadzhanov & Obrubov, 1992) • Previous age estimates – QUA, ARI, SDA, NDA => 2200 - 7000 years Jones & Jones (1993), Wu & Williams (1993), Neslusan et al. (2013) • Recently ARI, SDA, NDA associated with the Marsden group of comets – Ohtsuka et al. (2003), Sekanina & Chodas (2005), Jenniskens (2012) – ARI, SDA, NDA, along with Marsden group of comets, formed between 100 AD – 900 AD Our work • Simulations of stream formation. – 96P/Machholz => 20000 BC – Marsden group (P/1999 J6) => 100 AD • We find by simultaneously fitting shower profiles, radiant and orbital elements that: 1. We find that 96P contributes to all 8 showers, whereas P/1999 J6 to only 3. 2. Marsden group of comets alone can not explain the observed duration of the showers. 3. The complex is much older that previously suggested Results from simulations Showers of 96P/Machholz Showers of P/1999 J6 Meteoroid ejection 20000 BC Meteoroid ejection onset 100 AD QUA NID ARI NDA ARI SDA DLT SDA KVE TCA KVE 90 <-- 0 <-- 270 <--180 <-- 90 90 <-- 0 <-- 270 <--180 <-- 90 Southern Delta Aquariids (SDA) Age: 100 AD Parent body: Marsden group of comets (P/1999 J6) Sekanina & Chodas (2005) Ejection epoch Residuals Grey – observations Red - Simulations SDA – Continued Meteoroid Ejection onset time: 20000 BC Assumed parent body: 96P/Machholz Ejection epoch Residuals Grey – observations Red - Simulations SDA – Combined profile Marsden group (P/1999 J6) => 100 AD 96P/Machholz => 20000 BC Ejection epoch Residuals Grey – observations Red - Simulations SDA – radiant drift and position SDA Daytime Lambda Taurids Origin from comet 96P/Machholz => 20000 BC Ejection epoch Residuals Grey – observations Red - Simulations Radiant drift Daytime Lambda Taurids Radiant position DLT Cont.