Meteor Showers
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A&A 598, A40 (2017) Astronomy DOI: 10.1051/0004-6361/201629659 & c ESO 2017 Astrophysics Separation and confirmation of showers? L. Neslušan1 and M. Hajduková, Jr.2 1 Astronomical Institute, Slovak Academy of Sciences, 05960 Tatranska Lomnica, Slovak Republic e-mail: [email protected] 2 Astronomical Institute, Slovak Academy of Sciences, Dubravska cesta 9, 84504 Bratislava, Slovak Republic e-mail: [email protected] Received 6 September 2016 / Accepted 30 October 2016 ABSTRACT Aims. Using IAU MDC photographic, IAU MDC CAMS video, SonotaCo video, and EDMOND video databases, we aim to separate all provable annual meteor showers from each of these databases. We intend to reveal the problems inherent in this procedure and answer the question whether the databases are complete and the methods of separation used are reliable. We aim to evaluate the statistical significance of each separated shower. In this respect, we intend to give a list of reliably separated showers rather than a list of the maximum possible number of showers. Methods. To separate the showers, we simultaneously used two methods. The use of two methods enables us to compare their results, and this can indicate the reliability of the methods. To evaluate the statistical significance, we suggest a new method based on the ideas of the break-point method. Results. We give a compilation of the showers from all four databases using both methods. Using the first (second) method, we separated 107 (133) showers, which are in at least one of the databases used. These relatively low numbers are a consequence of discarding any candidate shower with a poor statistical significance. -
Assessing Risk from Dangerous Meteoroids in Main Meteor Showers Andrey Murtazov
Proceedings of the IMC, Mistelbach, 2015 155 Assessing risk from dangerous meteoroids in main meteor showers Andrey Murtazov Astronomical observatory, Ryazan State University, Ryazan, Russia [email protected] The risk from dangerous meteoroids in main meteor showers is calculated. The showers were: Quadrantids–2014; Eta Aquariids–2013, Perseids–2014 and Geminids–2014. The computed results for the risks during the shower periods of activity and near the maximum are provided. 1 Introduction The activity periods of these showers (IMO) are: Quadrantids–2014; 1d; Eta Aquariids–2013; 10d, Bright meteors are of serious hazard for space vehicles. Perseids–2014; 14d and Geminids–2014; 4d. A lot of attention has been recently paid to meteor Our calculations have shown that the average collisions N investigations in the context of the different types of of dangerous meteoroids for these showers in their hazards caused by comparatively small meteoroids. activity periods are: Furthermore, the investigation of risk distribution related Quadrantids–2014: N = (2.6 ± 0.5)10-2 km-2; to collisions of meteoroids over 1 mm in diameter with Eta Aquariids–2013: N = (2.8)10-1 km-2; space vehicles is quite important for the long-term Perseids–2014: N = (8.4 ± 0.8)10-2 km-2; forecast regarding the development of space research and Geminids–2014: N = (4.8 ± 0.8)10-2 km-2. circumterrestrial ecology problems (Beech, et al., 1997; Wiegert, Vaubaillon, 2009). Consequently, the average value of collision risk was: Considered hazardous are the meteoroids that create -2 -1 Quadrantids–2014: R = 0.03 km day ; meteors brighter than magnitude 0. -
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). -
17. a Working List of Meteor Streams
PRECEDING PAGE BLANK NOT FILMED. 17. A Working List of Meteor Streams ALLAN F. COOK Smithsonian Astrophysical Observatory Cambridge, Massachusetts HIS WORKING LIST which starts on the next is convinced do exist. It is perhaps still too corn- page has been compiled from the following prehensive in that there arc six streams with sources: activity near the threshold of detection by pho- tography not related to any known comet and (1) A selection by myself (Cook, 1973) from not sho_m to be active for as long as a decade. a list by Lindblad (1971a), which he found Unless activity can be confirmed in earlier or from a computer search among 2401 orbits of later years or unless an associated comet ap- meteors photographed by the Harvard Super- pears, these streams should probably be dropped Sehmidt cameras in New Mexico (McCrosky and from a later version of this list. The author will Posen, 1961) be much more receptive to suggestions for dele- (2) Five additional radiants found by tions from this list than he will be to suggestions McCrosky and Posen (1959) by a visual search for additions I;o it. Clear evidence that the thresh- among the radiants and velocities of the same old for visual detection of a stream has been 2401 meteors passed (as in the case of the June Lyrids) should (3) A further visual search among these qualify it for permanent inclusion. radiants and velocities by Cook, Lindblad, A comment on the matching sets of orbits is Marsden, McCrosky, and Posen (1973) in order. It is the directions of perihelion that (4) A computer search -
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. -
Meteor Showers # 11.Pptx
20-05-31 Meteor Showers Adolf Vollmy Sources of Meteors • Comets • Asteroids • Reentering debris C/2019 Y4 Atlas Brett Hardy 1 20-05-31 Terminology • Meteoroid • Meteor • Meteorite • Fireball • Bolide • Sporadic • Meteor Shower • Meteor Storm Meteors in Our Atmosphere • Mesosphere • Atmospheric heating • Radiant • Zenithal Hourly Rate (ZHR) 2 20-05-31 Equipment Lounge chair Blanket or sleeping bag Hot beverage Bug repellant - ThermaCELL Camera & tripod Tracking Viewing Considerations • Preparation ! Locate constellation ! Take a nap and set alarm ! Practice photography • Location: dark & unobstructed • Time: midnight to dawn https://earthsky.org/astronomy- essentials/earthskys-meteor-shower- guide https://www.amsmeteors.org/meteor- showers/meteor-shower-calendar/ • Where to look: 50° up & 45-60° from radiant • Challenges: fatigue, cold, insects, Moon • Recording observations ! Sky map, pen, red light & clipboard ! Time, position & location ! Recording device & time piece • Binoculars Getty 3 20-05-31 Meteor Showers • 112 confirmed meteor showers • 695 awaiting confirmation • Naming Convention ! C/2019 Y4 (Atlas) ! (3200) Phaethon June Tau Herculids (m) Parent body: 73P/Schwassmann-Wachmann Peak: June 2 – ZHR = 3 Slow moving – 15 km/s Moon: Waning Gibbous June Bootids (m) Parent body: 7p/Pons-Winnecke Peak: June 27– ZHR = variable Slow moving – 14 km/s Moon: Waxing Crescent Perseid by Brian Colville 4 20-05-31 July Delta Aquarids Parent body: 96P/Machholz Peak: July 28 – ZHR = 20 Intermediate moving – 41 km/s Moon: Waxing Gibbous Alpha -
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 -
Meteor Showers from Active Asteroids and Dormant Comets in Near-Earth
Planetary and Space Planetary and Space Science 00 (2018) 1–11 Science Meteor showers from active asteroids and dormant comets in near-Earth space: a review Quan-Zhi Ye Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA 91125, U.S.A. Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125, U.S.A. Abstract Small bodies in the solar system are conventionally classified into asteroids and comets. However, it is recently found that a small number of objects can exhibit properties of both asteroids and comets. Some are more consistent with asteroids despite episodic ejections and are labeled as “active asteroids”, while some might be aging comets with depleting volatiles. Ejecta produced by active asteroids and/or dormant comets are potentially detectable as meteor showers at the Earth if they are in Earth-crossing orbits, allowing us to retrieve information about the historic activities of these objects. Meteor showers from small bodies with low and/or intermittent activities are usually weak, making shower confirmation and parent association challenging. We show that statistical tests are useful for identifying likely parent-shower pairs. Comprehensive analyses of physical and dynamical properties of meteor showers can lead to deepen understanding on the history of their parents. Meteor outbursts can trace to recent episodic ejections from the parents, and “orphan” showers may point to historic disintegration events. The flourish of NEO and meteor surveys during the past decade has produced a number of high-confidence parent-shower associations, most have not been studied in detail. More work is needed to understand the formation and evolution of these parent-shower pairs. -
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. -
The 2019 Meteor Shower Activity Forecast for Low Earth Orbit 1 Overview
NASA METEOROID ENVIRONMENT OFFICE The 2019 meteor shower activity forecast for low Earth orbit Issued 15 October 2018 The purpose of this document is to provide a forecast of major meteor shower activity in low Earth orbit. Several meteor showers – the Draconids, Perseids, eta Aquariids, Orionids, and potentially the Androme- dids – are predicted to exhibit increased rates in 2019. However, no storms (meteor showers with visual rates exceeding 1000 [1, 2]) are predicted. 1 Overview Both the MSFC stream model [3] and the Egal et al. Draconid model [4] predict a second Draconid outburst in 2019. The 2019 Draconids are expected to have nearly the same level of activity as the 2018 Draconids, which reached a zenithal hourly rate (or ZHR) of about 100. Twin outbursts also occurred in 2011 and 2012 [5, 6]. The Perseids, eta Aquariids, and Orionids are expected to show mild enhancements over their baseline activity level in 2019. The Perseids are expected to be slightly more active in 2019 than in 2018, with a peak ZHR around 112. The eta Aquariids and Orionids, which belong to a single meteoroid stream generated by comet 1P/Halley, are thought to have a 12-year activity cycle and are currently increasing in activity from year to year. A review of eta Aquariid literature [7, 8, 9, 10] also indicates that the overall activity level is higher than previously believed, and this is reflected in higher forecasted rates (a ZHR of 75) and fluxes for this shower. We may see enhanced beta Taurid activity in 2019. The beta Taurids are part of the same stream as the Northern and Southern Taurids but produce daytime meteors. -
„Ordinary“ Showers
„Ordinary“ Showers # MDC Show Shower Name MDC Number Solar Longitude Right Declination Vgeo Comment Num Code Status of Ascension ber Meteors Mean/ Max Interval Mean Drift Mean Drift Mean Drift [°] [°] [°] [°] [°] [°] [km/s] [km/s] 1 40 ZCY zeta Cygnids W 500 16 13-20 302 +0.3 +40 +0.2 40 - NM; SS: α,δ,v geo ; DM: δ 2 131 DAL delta Aquilids W 200 20 17-23 308 +1.0 +12 +0.3 63 - DM: δ 3 136 SLE sigma Leonids W 1,000 26 18-35 201 +0.6 +3 +0.0 19 -0.16 NM; DM: α,v geo 348 ARC April rho Cygnids E 4 1,700 33 13-44 314 +0.8 +44.5 +0.3 42 +0.00 ARC and NCY are identical 409 NCY nu Cygnids W 5 346 XHE x Herculids W 300 352 350-355 256 +0.8 +48.5 -0.0 35 - NM 6 6 LYR April Lyrids E 4,000 32.5 28-35 272.6 +0.65 +33.2 -0.3 45.5 +0.25 7 343 HVI H Virginids W 200 41 39-43 205 +0.7 -11 -0.5 17 - NM; SD; NAD 8 31 ETA eta Aquariids E 3,800 47 38-59 339.1 +0.64 -0.5 +0.33 66.5 +0.1 9 531 GAQ gamma Aquilids W 320 48 45-52 307 -0.1 +14.5 -0.1 66 - NM; SS: α; Part of N Apex? 10 145 ELY eta Lyrids E 800 50 45-52 291.3 +0.15 +43.4 +0.0 42.6 - Maybe active longer; DM: δ 11 520 MBC May beta Capricornids W 150 59 56-61 305 +0.7 -15 +0.3 68 - NM; WS; similar to 7CCA 12 362 JMC June mu Cassiopeiids W 150 71 69-74 11 +2.8 +53 +0.5 42 - WS; SS: α,δ,v geo 13 171 ARI Daytime Arietids E 70 77 74-79 44 +1.0 +23.5 +0.1 42 NM; Daytime shower; DM: v geo 14 164 NZC Northern June Aquilids E 200 82 79-84 293 +1.0 -12 -0.4 42 - DM: v geo 510 JRC NM; SD; NAD; short & strong; 15 June rho Cygnids W 190 84 83-85 320.4 +0.8 44.7 -0.8 48 - 521 JRP JRP is identical to JRC 16 410 DPI -
Meteor Activity Outlook for January 2-8, 2021
Meteor Activity Outlook for January 2-8, 2021 Daniel Bush captured this impressive fireball at 04:11 UT (23:11 CDT on Sept. 5) on 6 Septmeber 2020, from Albany, Missouri, USA. For more details on this particular event visit: https://fireball.amsmeteors.org/members/imo_view/event/2020/5020. Credit Daniel Bush January is best known for the Quadrantids, which have the potential of being the best shower of the year. Unfortunately, this shower is short lived and occurs during some of the worst weather in the northern hemisphere. Due to the high northern declination (celestial latitude) and short summer nights, little of this activity can be seen south of the equator. There are many very minor showers active throughout the month. Unfortunately, most of these produce less than 1 shower member per hour and do not add much to the overall activity total. Activity gets interesting as seen from the southern hemisphere as ill-defined radiants in Vela, Carina, and Crux become active this month. This activity occurs during the entire first quarter of the year and moves eastward into Centaurus in February and ends in March with activity in Norma and Lupus. Sporadic rates are generally similar in both hemispheres this month. Sporadic rates are falling though for observers in the northern hemisphere and rising as seen from the southern hemisphere. During this period, the moon reaches its last quarter phase on Wednesday January 6th. At this time, the moon is located 90 degrees west of the sun in the sky and will rise near midnight standard time.