Special Topic

ARTICLE: Comet Linear Special

by Léa Delleré

Comet C/1999 S4 Linear! "Comets are like cats. They have a tail and they do what they want." David Levy Note: This site will not get updated! Some external links may not work anymore! Most recent on top, scroll down for older material!  UPDATE May 2001:A dying comet exposes its secrets C/LINEAR's breakup sheds light on origins, Science reports  UPDATE October 2000: Scientists piece clues to comet’s wild ride UPDATE September: LATEST PICTURE OF COMET LINEAR! Click on image to enlarge Picture: Gordon Garradd. C/1999 S4 (LINEAR). 2000 08 21.38, sum of 3X60s exposures. North is up in this 17' X 13' field of view. This image shows the elongated remains of the nucleus, now becoming quite diffuse. It is scaled to represent the visual appearance though the telescope. Taken with a 45cm f/5.4 Newtonian + AP7 CCD from the Gene Shoemaker Planetary Society NEO grant from Loomberah NSW Australia. Copyright 2000© GordonGarradd. loomberah@ozemail.com.au  Source : Comet Observation Home Page UPDATE August 7: HUBBLE PICTURE OF COMET LINEAR!  Hubble sees missing pieces of Comet Linear! Click on image to enlarge Picture: R. Corradi and N. O'Mahoney, 2.5-m Isaac Newton Telescope. Above: This R-filtered image of Comet LINEAR's inner coma reveals no fragments brighter than 22nd magnitude. Comet LINEAR blew apart so thoroughly last week that astronomers can't find any sizable pieces from its fractured icy core. New groundbased images of the comet posted today revealed no fragments brighter than 22nd magnitude. The new data are fueling speculation that Comet LINEAR itself might have been the fragment of a larger body that passed through the inner solar system centuries ago.  Source : Space Weather News for August 4, 2000 UPDATE July 28: DEATH OF A COMET - LINEAR BLOWN APART!!! De Koméit as auserneegebrach an hechstens nach e puer Dee ze gesinn!!! :((   Picture by Roeser Observatory! The icy visitor from beyond the orbit of Neptune will soon be gone forever...  Informatiounen op dese Säiten: HUBBLE DISCOVER MISSING PIECES OF COMET LINEAR!!! August 2 Linear Picture! (animation, takes a while to load) Report from Observatory La Palma Comet Linear fizzes away Meltdown! Comet LINEAR continues to disintegrate and could disappear completely within a few days!!! :(( Telescope observes the death of Comet LINEAR! Hubble Sees Comet Linear Blow its Top! Comet erupts violently as Hubble watches Comet LINEAR misbehaves UPDATE July 22 Reportage vun der Comet Watch um Napoleonsgaard Bei engem kloren Himmel an engem zimlech kalen Nordwand haten sech eng 50 Leit um Napoleonsgaard afond, fir de Koméit Linear S4 ze gesinn. D’AAL ware mat 15 Teleskopen an 2 Spektiven vertrueden, dorënner e Mewlon 300 an eng 20x100 Miyauchi Spektiv. Géint 23:30 war et endlech däischter genuch an de Koméit as an de verschiddenen Okularen z’erkenne gewiecht, wat mat grousser Begeeschterung (oder war et vläicht Erliichterung?) kommentéiert ginn ass. De Schwäif huet sech däitlech ofgezeechent, geschätzte Magnitude: 6. Den RTL TV-Team huet sech och fir de Koméit intresséiert, de Reportage as den Dag duerno bruecht ginn. Obwuel de Linear S4 keen esou spektakuläre Koméit war wéi den Hale- Bopp an den Hyakutake, sou war et dach fir d’Amateurastronomen a jiddereen, deen en duerch en Okular vun engem Teleskop oder enger Spektiv konnt beobachten, ee faszinéirend “himmlescht” Schauspill. Verschidde Memberen hun de Koméit fotograféiert. D’Resultater deemnächst op dëser Säit! Comet Watch Report Under clear skies and a rather chilly northely wind about 50 persons met at the "Napoleonsgaard" to observe the comet S4 Linear. The AAL were well represented with 15 telescopes, 2 binoculars with a. o. 1 Mewlon 300 and 20x100 Miyauchi binoculars. At around 11:30 pm the sky was dark enough and the comet became visible in the eyepieces of the telescopes.The tail was recognizable at an assessed magnitude 6. This was noted with amazement (or was it relief?) Also the RTL television team was interested and their report was diffused the day after. Though S4 Linear was not as spectacular as Hale-Bopp or Hyakutake, it was nevertheless a fascinating heavenly sight for all participants trough a telescope or binoculars. Some members took pictures of the comet. Results will be published here soon. Biller vum Site: Fotograf: Raymond Kneip De Koméit Linear kënnt! De Koméit C/1999 S4 Linear ass de 27te September 1999 vum  LINEAR Search Project entdeckt ginn, wéi en nach 3.9 AU (astronomesch Einheeten: 1 AU = mëttels Entfernung Aerd-Sonn, 150 Millioune Km), dat si 580 Millioune Kilometer vun der Aerd, a 4.3 AU = 640 Millioune Kilometer vun der Sonn weg war. De 26. Juli kënnt den C/1999 S4 Linear an de Perihel, dat as de noste Punkt bei der Sonn, mat enger Distanz vun 114.5 Millioune Km ( 0.765 AU ) an den 23. Juli ass en am noste bei der Aerd, nämlech 56.306.704 Km (0.376387 AU ). No neiste Berechnungen as et wahrscheinlech den éischte passage vun dësem Koméit am banneschte Sonnesystem. Dat heescht datt et een dynamesch "neie" Koméit as. Seng Hellegkeet hänkt vill dovunner af, ob et e "gasegen" oder e "stëbsegen" Koméit as. Verschidde nei Koméiten behalen hir Hellegkeetskurv bäi, wa se méi no kommen, anerer, besonnesch déi gaseg, verléieren dann un Hellegkeet. De Koméit as vun der nördlecher Hemisphär aus gudd ze beobachten, well en Ufanks Juli während de fréie Mueresstonnen am Nordoste steet, a méi spéit am Mound owes am Nordwesten. De 19. Juli passéiert en tëscht der Aerd an der Sonn, allerdings ganz nördlech vun der Sonn, duefir as e souwuel am Nordwesten no Sonnenënnergang an duerno, wéi och am Nordosten virum Sonnenopgang ze beobachten. En as also zirkumpolar fir e puer Deeg. Virum 19. Juli as e besser mueres virum Sonnenopgang am Nordosten ze beobachten an no deem Datum besser owes am Nordwesten. No dësem passage wiesselt de Koméit dann op d'südlech Hemisphär. Loosse mer hoffen, datt de Koméit bis dohinner e schéine Schwäif entwéckelt huet, d'Bedingungen duefir si jiddferfalls ideal. Souguer de Mound spillt mat an interferéiert net allzevill um Oweshimmel, nom Vollmound vum 16.Juli wiesselt en nämlech rem op de Muereshimmel. Déi viraussiichtlech Hellegkeet vun de Koméiten as am Ufank ëmmer schwéier anzeschätzen. Déi éischt Evaluatioune gunge vun Magnitude 5 (déi schwaachste Stären am Ursa Minor/Klénge Bier oder Won) a méi rezent bis Mag 3, (dat as ongeféier sou hell wéi déi mëttelhellst Stären am klénge Bier). Am beschte sicht een eng méiglechst däischter Beobachtungsplaz, an et informéiert ee sech genee, wou de Koméit steet. Mat enger Spektiv as e gudd ze beobachten. Oder op d'AAL COMET LINEAR WATCH kommen, wou mir mat Teleskopen a Spektiven de Koméit beobachten. Rendez-Vous den 21. Juli, ab 21:00 Auer, um Napoleonsgaard bei Rammerech (Rambrouch). (Bei bedecktem Himmel as d'Beobachtung den Dag duerno, op der selwechter Plaz, selwecht Zäit.) click here for chart - hei clicken fir Stärekaart Comet Linear is coming! Comet C/1999 S4 Linear has been discovered by the  LINEAR Search Project on September 27th 1999 while it was located at 3.9 Astronomical Units (AU) (360 million miles, or 580 million km) from the earth and 4.3 AU (400 million miles, or 640 million km) from the sun. (1 AU = the average distance between the earth and the sun, or 93 million miles or 150 million km.) The most recent orbital calculations indicate that Comet LINEAR is probably a first-time visitor into our inner solar system, making it a dynamically new comet. Their brightness is very difficult to predict and the dusty or gassy nature of a comet can greatly modify the light curve. Perihelion takes place on July 26, 2000, at a distance of 0.765 AU (71.1 million miles, or 114.5 million km) from the sun. The comet is closest to the earth on July 23, at a distance of 0.372 AU (34.6 million miles, or 55.7 million km). It is well placed for the for observation from the northern hemisphere, being located in the northeast during the morning hours early in the month, and in the northwest during the evening hours late in the month. On July 19, it is far enough north of the sun that it will be circumpolar -- i.e., never setting but instead remaining above the horizon continuously -- from mid-northern latitudes for several days around that date. Prior to July 19 it is better viewed in the northeast morning sky before dawn, and afterward is better viewed in the northwest evening sky after dusk. After making its passage by the earth and sun it will be visible from the southern hemisphere. Moonlight won't be interfering very much with the comet's display; the moon will be in the evening sky early in the month and then, after full moon on the 16th, will be in the morning sky. The brightnesses of comets are notoriously unpredictable. Expectations vary from 5th magnitude (the faintest stars in the Little Dipper) to 3rd magnitude (this is about the same brightness as the "medium" stars in the Little Dipper). We advise to observe from a dark site, to get the necessary information where the comet is located and to equip yourself with a pair of binoculars. We invite the public to join the "AAL COMET LINEAR WATCH" where we will provide telescopes and binoculars. Meeting is at the "Napoleonsgaard" near Rambrouch, on July 21th at 21:00. If the sky is covered on that day, the observation will be reported to July 22th, same time, same place. (Quell/source: http://www.swisr.org/newcomet)  Weider Informatiounen am Web - More Linear Info: Monmouth Mobile Observer's weekly update Cometary Notes of Bureau des longitudes Total visual magnitude estimates COMET LINEAR - A BRIGHT COMET FOR THE NEW MILLENNIUM? Recent Observations - JPL Finder charts for C/1999 S4 (LINEAR) - JPL Astronomical Observation and Information Online-calculator (choose comets on the pop-up menu on the top) The LINEAR Project Page BBC article: Comet visible in binoculars

About the Author - Léa Delleré

Language may vary from the one used in the article.

Lea is a former secretary and an astronomy passionata since 1970 AAL member since 1990 and Web Coordinator since 1997. See the contact page to find out how to contact me. Chimaera's Lair

SPECIAL TOPICS HISTORY
Period	Subject Author	Language	Available Formats
May 2008	De Summerstärenhimmel	LU	PDF=2005.7kB
September 2006	Ein aussergewöhnlicher Abend mit John Dobson in Saarlouis	DE
April 2006	Total Solar Eclipse 2006	LU
May 2004	Venus Transit 2004	EN
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Apr/May 2001	Das Foucault'sche Pendelexperiment	DE
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Jan 2001	Die Jagd nach Exo-Planeten	EN	PDF=544.4kB
Sep/Oct 2000	Entdecker des Sonnensystems	EN
Jun/Jul 2000	Comet Linear Special	EN
Apr/May 2000	The Adventurous Search For The Astronomical Unit	EN
Mar 2000	Why the moon always shows us the same face	EN

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