DOCSLIB.ORG

The OBSERVER the Newsletter of the Twin City Amateur Astronomers, Inc

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The OBSERVER the Newsletter of the Twin City Amateur Astronomers, Inc The OBSERVER The Newsletter of the Twin City Amateur Astronomers, Inc. October 2003 Volume 28, Number 10 Observing Programs —William Carney OR A LONG TIME my interest the last year or so was Sandyʼs discus- In This Issue: waned in astronomy, due mainly to sion about the observing programs from a loss of a good friend and fellow Astronomical League and I was surprised Fobserver Weldon Schuette. But several to see from the hands that there were very years ago with the passing of time few people working on observing • Observing Programs...............1 I realized that I was missing programs. Looking for something to being with other fellow rekindle your love of astronomy? observers and friends and After purchasing Perhaps these may help... I sat down and won- some good eye- dered why I was not pieces I decided to • TCAA Calendar ........................1 observing. I finished start simple with Use our calendar to mark the Lunar Club in the Astronomical your calendar. ʻ99 but this still did Leagueʼs Urban not really rekindle Observing Club. • Power Observing @ SGO .......3 my interest. I came to At least I thought Just how fast can you do the realize that part of the it would be simple, Messier List? With an LX-200, problem was I needed new but from my location very fast! eyepieces and other equip- (almost downtown) it was ment, but with these purchased I quite a challenge. In the process • Sept. Observing Sessions......4 thought well maybe there is something of doing the program, I rekindled my Weʼve been busy in else. I finally realized that I was not chal- interest in doing more observing and in September... lenged or had the desire till recently to doing other observer programs as well. I try any observing other than some basics. even discovered a keen interest in observ- • POSs Past, Present & Future .4 One of the few meetings I attended in continued on page 2 ... and in October, too! Expand Your Mind @ the TCAA Monthly Meeting • The SGNC Chautauqua............6 10 November, 2003, 7 PM, ISU Planetarium The TCAA was there (well, at least a few of us were...) • Weather & the Internet.............8 A handsome stud writes TCAA Calendar about the weather. Monday, 27 October, 2003, 5:30-7:15 PM, SGO School Observing Session (SOS!) • HST Deep Field.........................9 See what 84 hours and the Saturday, 1 November, 2003, 6:00-8:00 PM, SGO HSTʼs newest camera can Public Observing Session do for you! Monday, 10 November, 2003, 7:00 PM, ISU Planetarium • Treasurerʼs Report ................10 TCAA Meeting. Presenter: Rebecca Wenning • TCAA Crossword................... 11 Saturday, 29 November, 2003, 6:00-8:00 PM, SGO Pencil? Wits? Go! Public Observing Session • Welcome Mat .........................12 2 The Observer The Newsletter of the TCAA, Inc. The Observer is a monthly publication of the Twin City Amateur Astronomers, Inc., a non- continued from p. 1 profit organization of amateur astronomers interested in studying astronomy and sharing ing more planetary nebulae. In fact, the If you are a beginner, start with the Uni- their hobby with the public. Astronomical League currently does not verse Sampler or Messier Club. You have an observing program specifically could try the Urban Observing Club, for planetary nebulae. but I recommend that for slightly more TCAA Officers experienced observers. Programs such as President Dan Meyer To recap, we are affiliated with the Lunar Club, Meteor Club and Planetary 309-874-2923 Astronomical League which has quite a Observers Club are also good starters for [email protected] few observing programs for members to beginners as well. For more experienced Vice-president Neale Leumkhl accomplish. When finished you get a nice observers you can try just about any of 309-378-4335 certificate and pin. I will list current pro- them, but you might start with the Lunar [email protected] grams below briefly. Club, Urban Observing Club, Herschel 3rd Director Jim Swindler 400, and Double Star Club . 309-452-3936 Lunar Club, Urban Observing Club, Uni- [email protected] verse Sampler Club, Binocular Messier There are a few basic tips I will share 4th Director Duane Yockey 309-452-3936 Club, Deep Sky Binocular Club South- with you on doing these programs. It does [email protected] ern Skies Binocular Club Messier Club, help a lot if you have good sky charts or a 5th Director Carl Wenning Herschel 400 Club, Herschel II Club, sky chart program that can print out cur- 309-438-2957 Caldwell Club, Arp Peculiar Galaxy Club rent sky maps. This can be very crucial [email protected] Galaxy Groups & Clusters Club Asteroid for finding a 8, 9, 10, 12 or greater deep Treasurer Duane Yockey Observing Club, Double Star Club, Earth sky object especially from light polluted 309-452-3936 Orbiting Satellite Observing Club Master areas. It also helps to list all the items in [email protected] Observer Club Meteor Club Planetary an observing program by constellation. Secretary Carl Wenning Observers Club, Sunspotters Club Sky- I currently have the Herschel 400 list in 309-438-2957 [email protected] puppy Club three large notebooks including several Property Manager Sandy McNamara printed charts for each item and sorted 309-379-2751 Some of these are self explanatory. Some by constellation. This allows you to pick [email protected] do require some hard work and even a constellation and observe all items in travel. I intend to do the Southern Skies that one then move on. I found that I Binocular Club and the Caldwell Club missed an object or two and had to wait The Observer Staff which require some travel to the southern six to nine monthʼs before it was visible Editors Michael Rogers hemisphere. I am currently working on again. For the Lunar Club, time listing is Jean Memken several programs including Herschel 400, very critical. For some craters and other objects on the Moon you only have one or Production Benjamin Rogers Asteroid Observing, Double Star, and Sarah Rogers Binocular Messier clubs and I plan to do two days observing time for them in any others in the future. Editorial Correspondence: continued on p. 7 The OBSERVER Editors 2206 Case Drive Bloomington, IL 61701 Articles, ads, etc., are due by the last weekend Support Your Local Planetarium! of each month. Items may be e-mailed to: [email protected], or [email protected] Dues $40.00 per household, per year $25.00 for members over 60 $25.00 for newsletter only $ 2.50 for a single newsletter copy 3 The Observer The Newsletter of the TCAA, Inc. Power Observing at the SGO The Observer is a monthly publication of the — Carl J. Wenning Twin City Amateur Astronomers, Inc., a non- profit organization of amateur astronomers interested in studying astronomy and sharing N FRIDAY AFTERNOON, Sep- included observations of 19 objects for a NGC 6790 in particular showed very pro- their hobby with the public. tember 19, I was returning from grand total of 71 in an hour and a half. nounced blue, even more discernable than two days of work in Springfield the famous “Blue Snowball” (NGC 7662) Owhen I drove by the SGO on my way During the session I found that there was in Andromeda. TCAA Officers back to Normal. The sky was very clear, no significant vibration in the telescope at low power; at least I was not bothered It has become evident that with the 12- President Dan Meyer and I decided then and there that I would 309-874-2923 go observing that evening. I felt that the by any ongoing shaking of the eyepiece inch LX200 even a relatively novice [email protected] conditions were ideal for becoming more image. I was still a bit dismayed by the amateur astronomer could view the entire Vice-president Neale Leumkhl familiar with the operation of the 12- lack of absolutely crisp images produced collection of Messier objects on a spring 309-378-4335 inch LX200. Earlier in the week Sandy by the telescope, but Iʼm beginning to evening, and all the Herschel objects in [email protected] McNamara had dropped off my key to wonder how much of the lack of defini- just a few sessions scattered over the 3rd Director Jim Swindler the observatory, and I was now an official tion might be due to the single eyepiece course of a few months. Imagine, it takes 309-452-3936 key holder in need of additional experi- that I used. This is something that still many capable observers using star-hop- [email protected] ence before working with people attend- needs to be determined. (Work on Satur- ping methods more than a year to view all 4th Director Duane Yockey day evening with other eyepieces showed 110 M-objects, and truly skilled observ- 309-452-3936 ing public observing sessions. I arrived at [email protected] the observatory shortly after sunset and the problem to be partially due to the eye- ers several years to view the entire list 5th Director Carl Wenning quickly aligned the telescope with the piece I was using on Friday evening.) Iʼm of 400 Herschel objects. Now it can be 309-438-2957 stars. I had decided earlier to put the tele- now a bit concerned, too, that the program done with very little exertion using the [email protected] scope through its paces, and see just how in the LX200 that calculates the position SGO. The power of the TCAA telescope Treasurer Duane Yockey many celestial objects I could find during of Mars has in it an error. I suspect that housed under the dome at the SGNC is 309-452-3936 the viewing session.
Load more

Recommended publications
  • Download This Article in PDF Format
    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.
    [Show full text]
  • 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
    [Show full text]
  • 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
    [Show full text]
  • 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.
    [Show full text]
  • 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.
    [Show full text]
  • Analysis of Historical Meteor and Meteor Shower Records: Korea, China and Japan
    Highlights of Astronomy, Volume 16 XXVIIIth IAU General Assembly, August 2012 c International Astronomical Union 2015 T. Montmerle, ed. doi:10.1017/S1743921314005079 Analysis of Historical Meteor and Meteor shower Records: Korea, China and Japan Hong-Jin Yang1, Changbom Park2 and Myeong-Gu Park3 1 Korea Astronomy and Space Science Institute, Korea email: [email protected] 2 Korea Institute for Advanced Study, Korea 3 Kyungpook National University, Korea Abstract. We have compiled and analyzed historical meter and meteor shower records in Ko- rean, Chinese, and Japanese chronicles. We have confirmed the peaks of Perseids and an excess due to the mixture of Orionids, north-Taurids, or Leonids through the Monte-Carlo test from the Korean records. The peaks persist for almostonethousandyears.Wehavealsoanalyzed seasonal variation of sporadic meteors from Korean records. Major features in Chinese meteor shower records are quite consistent with those of Korean records, particularly for the last millen- nium. Japanese records also show Perseids feature and Orionids/north-Taurids/Leonids feature, although they are less prominent compared to those of Korean or Chinese records. Keywords. meteors, meteor showers, historical records We have compiled and analyzed the meteor and meteor shower records in official Korean history books (Kim et al. 1145; Kim et al. 1451; Chunchugwan 1392-1863) dating from 57 B.C. to A.D. 1910, covering the Three Kingdoms period (from 57 B.C. to A.D. 918), Goryeo dynasty (from A.D. 918 to A.D. 1392), and Joseon dynasty (from A.D. 1392 to A.D. 1910). The books contain only a small number of meteor shower records in contrast to abundant meteor records.
    [Show full text]
  • Occurrence and Altitude of the Non-Specular Long-Lived Meteor Trails During Meteor Showers at High Latitudes
    EGU2020-1543 https://doi.org/10.5194/egusphere-egu2020-1543 EGU General Assembly 2020 © Author(s) 2021. This work is distributed under the Creative Commons Attribution 4.0 License. Occurrence and altitude of the non-specular long-lived meteor trails during meteor showers at high latitudes Alexander Kozlovsky1, Renata Lukianova2, and Mark Lester3 1University of Oulu, Sodankyla Geophysical Observatory, Sodankyla, Finland ([email protected]) 2Space Research Institute, Moscow, Russia 3Department of Physics and Astronomy, University of Leicester, Leicester, UK Meteoroids entering the Earth’s atmosphere produce ionized trails, which are detectable by radio sounding. Majority of such radar detections are the echoes from cylindrical ionized trails, which occur if the radar beam is perpendicular to the trail, i.e., the reflection is specular. Typically such echoes detected by VHF radars last less than one second. However, sometimes meteor radars (MR) observe unusually long-lived meteor echoes and these echoes are non-specular (LLNS echoes). The LLNS echoes last up to several tens of seconds and show highly variable amplitude of the radar return. The LLNS echoes are received from the non-field-aligned irregularities of ionization generated along trails of bright meteors and it is believed that key role in their generation belongs to the aerosol particles arising due to fragmentation and burning of large meteoroids. The occurrence and height distributions of LLNS are studied using MR observations at Sodankylä Geophysical Observatory (SGO, 67° 22' N, 26° 38' E, Finland) during 2008-2019. Two parameters are analyzed: the percentage and height distribution of LLNS echoes. These LLNS echoes constitute about 2% of all MR detections.
    [Show full text]
  • Activity of the Eta-Aquariid and Orionid Meteor Showers A
    Astronomy & Astrophysics manuscript no. Egal2020b ©ESO 2020 June 16, 2020 Activity of the Eta-Aquariid and Orionid meteor showers A. Egal1; 2; 3,?, P. G. Brown1; 2, J. Rendtel4, M. Campbell-Brown1; 2, and P. Wiegert1; 2 1 Department of Physics and Astronomy, The University of Western Ontario, London, Ontario N6A 3K7, Canada 2 Institute for Earth and Space Exploration (IESX), The University of Western Ontario, London, Ontario N6A 3K7, Canada 3 IMCCE, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, Univ. Lille, France 4 Leibniz-Institut f. Astrophysik Potsdam, An der Sternwarte 16, 14482 Potsdam, Germany, and International Meteor Organization, Eschenweg 16, 14476 Potsdam, Germany Received XYZ; accepted XYZ ABSTRACT Aims. We present a multi-instrumental, multidecadal analysis of the activity of the Eta-Aquariid and Orionid meteor showers for the purpose of constraining models of 1P/Halley’s meteoroid streams. Methods. The interannual variability of the showers’ peak activity and period of duration is investigated through the compilation of published visual and radar observations prior to 1985 and more recent measurements reported in the International Meteor Organization (IMO) Visual Meteor DataBase, by the IMO Video Meteor Network and by the Canadian Meteor Orbit Radar (CMOR). These techniques probe the range of meteoroid masses from submilligrams to grams. The η-Aquariids and Orionids activity duration, shape, maximum zenithal hourly rates (ZHR) values, and the solar longitude of annual peaks since 1985 are analyzed. When available, annual activity profiles recorded by each detection network were measured and are compared. Results. Observations from the three detection methods show generally good agreement in the showers’ shape, activity levels, and annual intensity variations.
    [Show full text]
  • Activity of the Eta-Aquariid and Orionid Meteor Showers A
    A&A 640, A58 (2020) Astronomy https://doi.org/10.1051/0004-6361/202038115 & © A. Egal et al. 2020 Astrophysics Activity of the Eta-Aquariid and Orionid meteor showers A. Egal1,2,3, P. G. Brown2,3, J. Rendtel4, M. Campbell-Brown2,3, and P. Wiegert2,3 1 IMCCE, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, Univ. Lille, France 2 Department of Physics and Astronomy, The University of Western Ontario, London, Ontario N6A 3K7, Canada e-mail: [email protected] 3 Institute for Earth and Space Exploration (IESX), The University of Western Ontario, London, Ontario N6A 3K7, Canada 4 Leibniz-Institut f. Astrophysik Potsdam, An der Sternwarte 16, 14482 Potsdam, Germany, and International Meteor Organization, Eschenweg 16, 14476 Potsdam, Germany Received 7 April 2020 / Accepted 10 June 2020 ABSTRACT Aims. We present a multi-instrumental, multidecadal analysis of the activity of the Eta-Aquariid and Orionid meteor showers for the purpose of constraining models of 1P/Halley’s meteoroid streams. Methods. The interannual variability of the showers’ peak activity and period of duration is investigated through the compilation of published visual and radar observations prior to 1985 and more recent measurements reported in the International Meteor Organiza- tion (IMO) Visual Meteor DataBase, by the IMO Video Meteor Network and by the Canadian Meteor Orbit Radar (CMOR). These techniques probe the range of meteoroid masses from submilligrams to grams. The η-Aquariids and Orionids activity duration, shape, maximum zenithal hourly rates values, and the solar longitude of annual peaks since 1985 are analyzed. When available, annual activity profiles recorded by each detection network were measured and are compared.
    [Show full text]
  • Peculiar Features of Α Monocerotid Tv Spectra. R
    61st Annual Meteoritical Society Meeting 5034.pdf PECULIAR FEATURES OF a MONOCEROTID TV SPECTRA. R. Stork1,2, J. Borovicka1, J. Bocek1, and M. Solc2, 1Astronomical Institute, Academy of Sciences of the Czech Republic, Fricova 1, CZ–25165 Ondrejov, Czech Republic ([email protected]), 2Institute of Astronomy, Charles University Prague, V Holesovickach 2, CZ– 18000 Prague 8, Czech Republic ([email protected]). An outburst of a Monocerotid meteors was widely (64 km/s), plus sign — Perseids (61 km/s), triangle — observed on November 22, 1995. Jenniskens et al. d Aquarids (44 km/s), diamond — Quadrantids found that a Monocerotids penetrate deeper into the (42 km/s), circle—Geminids (36 km/s) and x—very atmosphere than meteoroids of the Orionid stream or slow meteor (about 20 km/s). Perseid stream (meteoroids with similar velocity) and The Na/O ratio decreases with increasing velocity. that their light curves do not show flares [2]. The All showers agree with this dependence except of Jenniskens' results imply that a Monocerotids are a Monocerotids. Their points lie significantly lower more compact than meteoroids in other showers and (please, note the logarithmic scale) and it indicates can therefore contain lower amount of volatile ele- differences in meteoroids composition. The Na/Mg ments. We obtained four a Monocerotid spectra with ratio also confirm low amount of sodium in the a our television system on the Ondrejov observatory Monocerotid spectra. The N and O lines are both at- [1,3]. The spectra allowed us to test the above men- mospheric and their ratio should be constant, inde- tioned hypothesis.
    [Show full text]
  • 20010004237.Pdf
    RECOGNIZING LEONID METEOROIDS AMONG THE COLLECTED STRATOSPHERIC DUST ,t FRANS J.M. RIETMEIJER Institute of Meteoritics, Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, NM 87131, USA E-mail: fransjmr@unm, edu and PETER JENNISKENS SETI Institute, NASA ARC, MS 239-4, Moffett Field, CA, 94035, USA E-mail: pjenniskens @mail.arc.nasa.gov (Received 28 June 2000; Accepted 31 July 2000) Abstract. Three chemical groups of primary "silicate" spheres <30 p.m in diameter of cometary origin were collected in the lower stratosphere between 1981 May and 1994 July. The "silicate" sphere abundances represent an annual background from contributions by sporadic meteor and weak annual meteor shower activities. During two collection periods, from 06/22 until 08118, 1983 (U2015), and from 09/15-12/15, 1981 (W7027/7029), a higher number of spheres was collected compared to other periods of the year represented by the other collectors studied here. This study links two different data sets, viz. the NASSA/JSC Cosmic Dust Catalogs and peak activities of annual meteor showers, and identified high-velocity cometary sources for collected stratospheric "silicate" spheres. The majority of spheres on flag U2015 may originate from comet P/Swift-Tuttle (Perseids), while the majority of spheres on flags W7027/7029 could be from comet P/Halley (Orionids) or comet P/Tempel-Tuttle (Leonids). Variations in relative proportions of the Mg,Si,Ca 4- AI, Mg,Si 4. Fe and AI, Si,Ca spheres may offer a hint of chemical differences among high-velocity comets. Proof for the findings reported here might be obtained by targeted cosmic dust collections in the lower stratosphere including periods of meteor shower and storm activity.
    [Show full text]
  • Craters and Airbursts
    Craters and Airbursts • Most asteroids and comets fragments explode in the air as fireballs or airbursts; only the largest ones make craters. • Evidence indicates that the YDB impact into the Canadian ice sheet made ice-walled craters that melted away long ago. • The YDB impact also possibly created rocky craters, most likely along the edge of the ice sheet in Canada or underwater in the oceans. • Our group is planning expeditions to search for impact evidence and hidden craters, for example to North Dakota, Montana, Quebec, and Nova Scotia. The following pages show what could happen during an impact NOTE: this website is a brief, non-technical introduction to the YDB impact hypothesis. For in-depth information, go to “Publications” to find links to detailed scientific papers. NAME OF SHOWER NAME OF SHOWER Alpha Aurigids Leo Minorids Meteor Showers Alpha Bootids Leonids Alpha Capricornids Librids Alpha Carinids Lyrids Comet impacts are common, Alpha Centaurids Monocerotids Alpha Crucids Mu Virginids but usually, they are harmless Alpha Cygnids Northern Delta Aquariids Alpha Hydrids Northern Iota Aquariids Alpha Monocerotids Northern Taurids Alpha Scorpiids October Arietids • Earth is hit by 109 meteor Aries-triangulids Omega Capricornids Arietids Omega Scorpiids showers every year (listed at Beta Corona Austrinids Omicron Centaurids right), averaging 2 collisions Chi Orionids Orionids Coma Berenicids Perseids with streams each week Delta Aurigids Phoenicids Delta Cancrids Pi Eridanids Delta Eridanids Pi Puppids • Oddly, most “meteor showers”
    [Show full text]