THE COMET’S TALE
Newsletter of the Comet Section of the British Astronomical Association
Volume 8, No 2 (Issue 16), 2001 October
DEEP SPACE 1 ENCOUNTERS 19P/Borrelly
problem. All the science data ten years to facilitate the five Donald K. Yeomans were successfully received on upcoming cometary encounters Earth within a few hours after the provided by the CONTOUR, NASA/JPL, Near-Earth Object flyby itself. The DS1 spacecraft Stardust, Deep Impact, and program office was designed to test various space Rosetta spacecraft.
technologies including the ion On Saturday evening at 7:00 PM, drive engine that first ionizes For more information, see: sustained applause broke out in xenon and then electrostatically the Deep Space 1 spacecraft accelerated these charged http://nmp.jpl.nasa.gov/ds1/ control room at the Jet Propulsion particles to form a modest, but Laboratory. The first high continuous, rocket thrust. resolution images of comet's Borrelly nucleus had reached Earth (Figure 1). The images were sharper than expected and revealed a very dark, outgasing nucleus shaped a bit like a bowling pin except this bowling pin was nearly the size of Mt. Everest. Examination of the surface features reveals ridges, fault lines, and bright areas that are thought to be source regions for the nucleus' jets that emanate toward the solar direction. These Figure 2 This image of comet jets are thought to be the vaporization of the comet's ices as Borrelly's nucleus has been the active regions are heated by Figure 1 This black and white purposely overexposed to show sunlight (Figure 2). The strong image of comet Borrelly's nucleus the strongly collimated jets on the linearity, or collimation, of these was taken while the spacecraft sunward side of the nucleus. jets is a bit of a mystery that was about 3400 km from the These jets are thought to be scientists will have to solve in the comet. The dimensions of the composed mostly of water vapor near future. Although the nucleus are about 8 kilometers and entrained dust particles. infrared spectral data and charged long by at least 3.5 kilometers particle detector data have not yet wide. While the contrast of this Copyright Tumbling Stone 2001 been completely analyzed, this image has been altered to show information should help surface features, the entire Images: courtesy of NASA/JPL determine the composition of nucleus would appear coal black these gases and hence the nature to the naked eye. Contents of the parent ices of the comet's nucleus. Before running out of fuel, and Comet Section contacts 2 without the used of a star tracker Section news 2 While the Deep Space 1 to provide orientation information Section meeting 3 spacecraft (DS1) was not to the spacecraft, the DS1 Tales from the Past 3 designed to encounter a comet operations team had to work hard Comet Pons-Gambart 4 and lacked any dust shielding to to keep the spacecraft operating Predictions for 2002 5 protect it from the bullet-like dust and pointed properly. They did Professional Tales 7 particle environment through so with remarkable success. The Request for observations 13 which it was moving, DS1 lessons learned from this comet Review of observations 13 survived the flyby without a encounter will be used in the next
BAA COMET SECTION NEWSLETTER 2 THE COMET’S TALE
Comet Section contacts
Director: Jonathan Shanklin, 11 City Road, CAMBRIDGE. CB1 1DP, England. Phone: (+44) (0)1223 571250 (H) or (+44) (0)1223 221400 (W) Fax: (+44) (0)1223 221279 (W) or (+44) (0) 1223 571250 (H) E-Mail: [email protected] or [email protected] WWW page : http://www.ast.cam.ac.uk/~jds/
Assistant Director (Observations): Guy Hurst, 16 Westminster Close, Kempshott Rise, BASINGSTOKE, Hampshire. (and also Editor of RG22 4PP, England. The Astronomer magazine) Phone & Fax: (+44) (0)1256 471074 E-Mail: [email protected] or [email protected]
CCD Advisor: Nick James, 11 Tavistock Road, CHELMSFORD, Essex. CM1 5JL, England. Phone: (+44) (0)1245 354366 E-mail: [email protected]
Photographic Advisor: Michael Hendrie, Overbury, 33 Lexden Road, West Bergholt, COLCHESTER, Essex, CO6 3BX, England Phone: (+44) (0)1206 240021
Subscription to the Section newsletter costs £5 for two years, extended to three years for members who contribute to the work of the Section in any way, for example by submitting observations or articles. Renewals should be sent to the Director and cheques made payable to the BAA. Those due to renew should receive a reminder with this mailing.
Section news from the Director
Dear Section member, bright comets and electronic Mobberley, Michael Oates, submission of observations. One Gabriel Oksa, Roy Panther, Robin It has been rather a busy summer problem has been that every time Scagell, Jonathan Shanklin, for me, so this edition of the I've re-read it I've found further David Storey, Melvyn Taylor and comet's tail is a little late in points that I'd like to amend. Alex Vincent and also from: Jose appearing. The weather has not Hopefully I won't find any more! Aguiar, Alexandre Amorim, been very favourable for Alexander Baransky, Sandro observing, but the odd gap in the Many more observers are taking Baroni, Nicolas Biver, Reinder cloud has allowed me, and I hope up CCD imaging and submitting Bouma, Jose Carvajal, Tim you, to make occasional their images. Quite a few of these Cooper, Matyas Csukas, Fraser observations. Hopefully the get submitted as linear.jpg or Farrell, Mike Feist, Rafael autumn will be better and we will something similar. This makes it Ferrando, Stephen Getliffe, get good views of 2000 WM1 rather hard to identify once I've Antonio Giambersio, Guus (LINEAR) as it brightens on its archived it and I'm having to Gilein, Shelagh Godwin, Bjorn way to perihelion. Two spend a lot of time re-naming Granslo, Roberto Haver, Michael significant comet discoveries have images. Please try and use the Jager, Andreas Kammerer, Paul been made - 2001 Q2 discovered standard format of Kemp, Heinz Kerner, Martin by amateur Vance Petriew at a comet_yyyymmdd_(hhmm)_obser Lehky, Rolando Ligustri, Pepe star party and 2001 Q4 (NEAT) ver.img where (hhmm) is Manteca, Michael Mattiazzo, discovered a long way from optional. As an example Maik Meyer, Antonio Milani, perihelion and which may become 2001a2_20010701_sha.jpg would Yurij Nesterov, Andrew Pearce, be an image of 2001a2 that I took Stuart Rae, Maciej Reszelski, a prominent object in 2004. In st addition Deep Space 1 flew past on July 1 . More details are on Tony Scarmato, Carlos Segarro, 19P/Borrelly and produced some the web page and in the Section Giovanni Sostero, Graham Wolf, exciting images of the comet. guide. Seiichi Yoshida (apologies for any errors or omissions). Without The revised edition of the Section Since the last newsletter these contributions it would be Guide to Observing Comets is observations or contributions have impossible to produce the taking a little longer to produce been received from the following comprehensive light curves that than anticipated should be BAA members: Tom Boles, Neil appear in each issue of The available at BAA events or Bone, Len Entwisle, John Comet’s Tale. through the BAA Office early Fletcher, Mario Frassatti, Maurice next year. The new edition has Gavin, Peter Grego, Werner Comets under observation significant changes, including Hasubick, Guy Hurst, Nick James, include: 19P/Borrelly, revised sections on comet Albert Jones, John Mackey, Nick 24P/Schaumasse, discovery procedures, CCD Martin, Steve Martin, John 29P/Schwassmann-Wachmann, observations, observing very McCue, Cliff Meredith, Martin 44P/Reinmuth, 45P/Honda-
BAA COMET SECTION NEWSLETTER 2001 October 3
Mrkos-Pajdusakova, take place prior to the afternoon lunch through the BAA office, 74P/Smirnova-Chernykh, 1999 J2 BAA meeting, starting at enclosing a cheque payable to the (Skiff), 1999 T1 (McNaught- 10:30am for coffee. The main BAA. If you would like a Hartley), 1999 T2 (LINEAR), speakers are Alan Fitzsimmons of vegetarian meal please state this 1999 U4 (Catalina-Skiff), 1999 Queen’s University of Belfast clearly. The cost of lunch is not Y1 (LINEAR), 2000 CT54 speaking on "Big comets and known at the time of going to (LINEAR), 2000 OF8 little comets: how many of each" press, but will be about £5 - £10; (Spacewatch), 2000 SV74 and Giovanni Sostero of the exact price will be given on (LINEAR), 2000 WM1 Remanzacco Observatory in Italy, the Section and BAA Web pages, (LINEAR), 2001 A2 (LINEAR), speaking on his experiences of in a BAA Circular and in the 2001 B2 (NEAT), 2001 HT50 CCD imaging. I'm allowing Journal. The booking deadline is (LINEAR-NEAT), 2001 K3 plenty of time for informal 2002 February 1 and there is a (Skiff), 2000 K5 (LINEAR), 2001 discussion over coffee, and lunch limit of 75 places. If you would MD7 (LINEAR), 2001 Q2 will be available at Savile Row, so like to make a provisional (Petriew) and 2001 Q6 (NEAT). do come along and make a day of booking let me know. Hopefully it. After lunch the main BAA stocks of the revised Section Section Meeting meeting begins at 14:30, with the Observing Guide will be available main speakers being David on the day! Finally some details about the Whitehouse speaking on 'A Section meeting on February 23. biography of the Moon' and Jonathan Shanklin This will be at the Scientific Melvyn Taylor on 'Variable Societies Lecture Theatre at Stars'. The meeting will also Savile Row in London and will feature Martin Mobberley's famous Sky Notes. Please book
Tales from the Past
This section gives a few excerpts 100 Years Ago: The May some weeks or months before it from past RAS Monthly Notices, Journal notes 'The first comet of was discovered, so that it seemed and BAA Journals Sky. the new century is one of a rather strange it was not discovered sensational nature. It is probably sooner. This was a point that 150 Years Ago: An astrometric the brightest comet that has might make comet seekers feel observation of Faye's comet by appeared since 1882'. [comet ashamed of themselves. It was Professor Challis with the 1901 G1 'Great Comet'] A note possible that the comet might Northumberland equatorial in from W G Lavender at Willow have been seen at the total eclipse Cambridge on March 4 has the Dam Camp, near Mafeking sent in Sumatra. Several newspaper note 'Of the last degree of on April 25 notes: 'We have to reports said that it had been seen faintness on account of the stand to arms at 5.30 every from England, but sadly they zodiacal light: could scarcely be morning, and it is then, of course, were false. Captain Noble observed.'. [I wish this were still dark. In the east there has been commented how carefully one true today, as light pollution is for two days a most beautiful ought to eschew newspapers when comet - due east, almost end on - they required any real now the major enemy] th th 24 and 25 April, just above the astronomical information. If the rising sun; brighter today than statements which he had seen in yesterday'. The Times reported some of the newspapers had any that Botha sent a message to his foundation in fact, this new comet forces saying that this comet was must have squirmed round the the presage of peace and sun like one of the penny snakes independence for the Boers. The which were sold in the streets! At Daily Mail reported that a soldier the June meeting Mr Chambers had written home describing it described his observations of a like a veldt fire with a rocket on tail in detail and said that it was top of it. At the May meeting Mr definitely there on May 1, but not Crommelin showed a diagram of on the two following nights, but the positions of the comet on the he could not otherwise explain the The Northumberland equatorial epidiascope. There had been a lot observation. Lantern slides of as it is today. The dome was of confusion over the comet. observations and drawings of the replaced in the 1930s, and the Yerkes observatory had reported comet were exhibited but seeing a bright object 15 degrees unfortunately when slides from telescope had a new lens in 1988 th north of the sun on April 26 and photos of recent comets were to mark its 150 anniversary. Mr Chambers reported seeing a being shown for comparison, the Much of the rest of the telescope comet's tail in the morning sky at acetylene lamp exploded, is unchanged since Professor 3.00 am. It later transpired that fortunately without doing any Challis observed with it. For neither of these reports matched damage. The final issue for the the real comet and comet seekers session includes a paper from Rev more details see had wasted a lot of time in J T Bird, Chaplain to Her http://www.ast.cam.ac.uk/IoA/nort searching for it. Mr Crommelin Majesty's Forces in the Transvaal. humberland.html said that the comet must have He describes his observations of been well placed for observation the great comet and also describes BAA COMET SECTION NEWSLETTER 4 THE COMET’S TALE the ideas of the Kaffirs about the 50 Years Ago: During the May comets. This generated comet. He notes that these were meeting Dr Merton reported on considerable discussion on split remarkably similar to those of observations of comet 1950b comets and motion in comet tails. Britain a few centuries earlier and Minkowski by Albert Jones, that it portended plague or war. drawings of comet 2P/Encke by George Alcock and several other
Awaiting Comet P/Pons-Gambart Volker Kasten, Garbsen, Germany
It is often a difficult task to resulting in a period of revolution backward in time until 1110, predict the behaviour of a comet. of 65.58 years for Pons-Gambart starting from the year 1827. The For example, no one knows for in 1827, the eccentricity of its starting elements were chosen sure the evolution of a comet's orbit being e = 0.9503946. With from GUIDE7, with the exception brightness or tail. And there are these elements, the next of the eccentricity e, which I still a few periodic comets with perihelion of the comet would be varied in the range e=0.943 to poorly known orbits, making as late as 2022 Jan 31. e=0.952, corresponding to predictions about their next osculating periods of revolution in perihelion date very uncertain. In addition, the authors present a 1827 from 53 to 69 years. One prominent example was table of previous perihelion times comet P/Swift-Tuttle, the of Pons-Gambart, starting from In the adjacent figure, the progenitor of the Perseids, which the year -194 until 2022. resulting perihelion times are finally came to perihelion in According to this table, there plotted as a function of the 1992, ten years later than most should have been five additional osculating eccentricity in 1827. had expected. perihelia with good observing The "predicted" perihelion in conditions after the apparition of 1110 is indicated by a horizontal A similar case is that of comet 1110, including that of 1827. But line. Integrations performed with P/Pons-Gambart. This periodic there is only one historical record REDSHIFT 3 are labelled by a comet was only seen at one of a comet in 1239, which could cross (+), those computed with apparition, in 1827, when it have been comet Pons-Gambart. SOLEX 7 are shown as a circle passed perihelion on June 7. Due According to Hasegawa and (o); the Hasegawa-Nakano- to investigations by Ogura (1917) Nakano, a more recent perihelion solution is marked with a red and Nakano (1978), the period of passage took place on 1892 June circle. The results of both used revolution seems to be in the 12. With this perihelion date, the programs seem to be consistent. range of 46 - 67 years. In 1979, comet should have been visible as Also, some tests with DANCE Hasegawa considered the possible a 4 mag circumpolar object in the yield fairly similar results. identity P/Pons-Gambart = northern sky at the end of June of C/1110 K1. According to his that year, strolling through the As the figure demonstrates, there computations, comet C/1110 K1 Big Dipper at the beginning of are several possible intervals for had fairly similar elements, July with a magnitude of 5.5 mag. the eccentricity in 1827 that yield reaching perihelion on 1110 May However, no appropriate comet perihelia not far from the year 18. More about comet C/1110 K1 was observed. It seems unlikely 1110. The first such interval goes can be found in Gary Kronks to assume that such a bright from e=0.9446 to 0.9455 with book "Cometography", Volume 1, object was simply overseen in computed perihelion times p. 193 ff. 1892. Thus, if one is not willing between 1103 and 1112. Given to accept the ad hoc assumption such eccentricities, Pons-Gambart that the comet was unusually faint would have returned as early as during this apparition, serious 1990 - 1995, but the comet was doubts arise about the given not discovered during those years. perihelion time in 1892. As a consequence, the orbital The solution e=0.9503946 of resolution of Hasegawa and Hasegawa and Nakano fits very Nakano for Pons-Gambart in well in this figure, lying in the 1827 must be considered as interval e=0.9499 - 0.951 of uncertain. possible values for the eccentricity. As already I therefore found it interesting to mentioned above, in this case we make my own investigations have to wait another twenty years regarding the orbit of comet Pons- for the next return of comet Pons- Gambart. With the help of Gambart. integration machines in In their paper "Periodic Comets REDSHIFT3, SOLEX 7.0 (a However, there is some hope for Found in Historical Records" public- domain program written an earlier return of the comet. As (Publ. Astron. Soc. Japan 47, by Aldo Vitagliano) and DANCE can be seen from the figure, there 699-710, 1995), Hasegawa and OF THE PLANETS, I integrated are two other good fits for the Nakano tried to link the orbits of various sets of osculating eccentricity, namely around Pons-Gambart and 1110 K1, elements of Pons-Gambart e=0.94667 and at the sharply BAA COMET SECTION NEWSLETTER 2001 October 5 defined value e=0.948379, were the end of the year 2003 seems to the perihelia make a steep jump Integrating from 1827 onward, be very unlikely. backward in time (resulting in 12 the former value of e yields the revolutions of the comet until next return at the end of the year See also the article by Andreas 1827 in each case). This jump 2003, while the latter value Kammerer published in The could have its origin in the 14th results in a perihelion in 2012. Comet's Tale in 1997 November, century, where due to DANCE Anyway, if the comet has not which is additionally available at the comet in 1365 had an already been overlooked in recent http://www.fg- aphelion unusual far from the years and has yet to come, a kometen.de/ponsetab.htm sun, although the program didn't return of Pons-Gambart prior to reveal any single reason for this.
Comet Prospects for 2002
2002 sees a number of returns of the comet, the June Bootids, when at its brightest (11m) at the periodic comets, however none of occurred on 1998 June 27.6. end of the year. them are particularly exciting. The brightest periodic comet of It will be a morning object, 29P/Schwassmann-Wachmann 1 the year is predicted to be becoming visible in February and is an annual comet which has P/Brewington, which is making reaching 11th magnitude in May frequent outbursts and seems to its first predicted return early in after which it is unfavourably be more often active than not at 2003 and this comet may reach placed for observation from the the moment, though it rarely gets 10th magnitude at the end of the UK. Observers at lower latitudes brighter than 12m. It spends the year. Several long period comets will be able to follow it until year in Capricornus reaching discovered in previous years are September. It moves eastwards, opposition in early August, fairly still visible. Theories on the being in Serpens in February, close to Neptune. The comet is structure of comets suggest that Ophiuchus in March, Aquila in an ideal target for those equipped any comet could fragment at any April and Aquarius in May. with CCDs and it should be time, so it is worth keeping an eye observed at every opportunity. on some of the fainter periodic Comet 19P/Borrelly reached Unfortunately opportunities for comets, which are often ignored. perihelion in September 2001 and UK observers are limited, as its This would make a useful project begins the year at 11m moving altitude will not exceed 20° from for CCD observers. Ephemerides northward in Canes Venatici. It this country. for new and currently observable remains quite well placed as it comets are published in the fades, passing into Ursa Major in Carl A Wirtanen discovered Circulars, Comet Section late February when it is 12th 46P/Wirtanen at Lick in 1948. It Newsletters and on the Section, magnitude. is in a chaotic orbit, and its CBAT and Seiichi Yoshida's web perihelion distance was much pages. Complete ephemerides 22P/Kopff was discovered reduced due to approaches to and magnitude parameters for all photographically by A Kopff at Jupiter in 1972 and 1984. It has comets predicted to be brighter Konigstuhl Observatory in 1906, been reported to outburst, but than about 18m are given in the when it was around 11m. The BAA data suggests that it was just International Comet Quarterly next return was unfavourable, but rejuvenated after the perihelion Handbook; details of subscription it has been seen at every return distance was reduced. It is a to the ICQ are available from the since then. Following an target for the Rosetta mission. A comet section Director. The encounter with Jupiter in 1942/43 December perihelion would give a section booklet on comet its period was reduced and the close approach to the Earth, observing is available from the perihelion distance decreased to however the present period is BAA office or the Director; a new 1.5 AU. The following return exactly 5.5 years so that perihelia edition is at the printers. was one of its best and it reached alternate between March and 8m. The next return was unusual, September. 7P/Pons-Winnecke was in that it was 3m fainter than discovered by Jean Louis Pons predicted until perihelion, when it The comet is also a morning with a 0.12-m refractor at brightened by 2m. It suffered object. More southerly placed Marseilles in 1819, but was then another encounter with Jupiter in observers may pick it up in June, lost until rediscovered by 1954, but this made significant but UK observers will probably Friedrich August Theodor changes only to the angular not find it until August, when it is Winnecke with a 0.11-m refractor elements. 1964 was another good fading from its best magnitude of in Bonn in 1858. He return and the comet reached 9m. 11. The solar elongation only demonstrated the identity and increases from around 40º to 60º recovered the comet in 1869. The UK observers may pick up the by the end of the year, so it is perihelion distance has slowly comet in March, when it is at never very well placed. In June it been increasing since the early opposition and follow it as it is in Cetus, moving into Taurus in 1800s. It can make close retrogrades in Virgo until May, July, Gemini in August and Virgo approaches to the Earth and did but the comet is only 13th in November. so in 1927 (0.04 AU), 1939 magnitude. Although it continues (0.11), 1892 (0.12), 1819 (0.13) to brighten, the solar elongation 67P/Churyumov-Gerasimenko and 1921 (0.14). An outburst of decreases and it is poorly placed was discovered in 1969 the meteor shower associated with September, by Klim Churyumov BAA COMET SECTION NEWSLETTER 6 THE COMET’S TALE and Svetlana Gerasimenko on a ending the year on the border of reaches 17m when at opposition in plate taken for 32P/Comas Sola at Leo and Virgo. June in Sagittarius. CCD V Alma Ata observatory. It reached magnitudes of Chiron would be of its present orbit after a very close 81P/Wild 2 is a new comet that particular interest as observations encounter (0.05 AU) with Jupiter made a very close (0.006 AU) show that its absolute magnitude in 1959, which reduced the approach to Jupiter in September varies erratically. It was at perihelion distance from 2.74 to 1974. Prior to this it was in a 40 perihelion in 1996 when it was 1.28 AU. At a good apparition, year orbit that had perihelion at 5 8.5 AU from the Sun and will be such as in 1982, when it AU and aphelion at 25 AU. The nearly 19 AU from the Sun at approached the Earth to 0.4 AU comet was discovered by Paul aphelion in around 50 years time. and was well observed by the Wild with the 40/60-cm Schmidt comet section, it can reach 9m. at Zimmerwald on 1978 January 6. The Stardust spacecraft is due The comet is another morning to visit the comet in 2004 and object, and even at best it recover material for return to probably won’t exceed 12th earth in 2006. magnitude. Southern observers may pick it up around the solstice, The comet is at opposition in but from the UK we won’t pick it Taurus in December when it will up before August, when it will be be around magnitude 13.5. It will fading. Again the elongation is brighten into 2003, when it is at 95P/Chiron imaged by Maurice not good, increasing from around perihelion, but is too close to the 50º to 100º at the end of the year. Sun for observation when at its Gavin in 1999 July. The comet’s track closely brightest (11m). parallels that of 46P/Wirtanen, entering Gemini in August and 95P/Chiron is an unusual comet in that it is also asteroid 2060. It
Comets reaching perihelion in 2002 Comet T q P N H1 K1 1999 F1 (Catalina) Feb 13.7 5.79 5.0 7.5 2000 SV74 (LINEAR) May 1.3 3.54 5.0 10.0 2000 WM1 (LINEAR) Jan 22.7 0.56 6.5 10.0 2001 C2 (LINEAR) Mar 28.3 5.10 6.0 10.0 2001 K5 (LINEAR) Oct 12.1 5.18 2.5 10.0 2001 N2 (LINEAR) Aug 19.9 2.67 7.5 10.0 2001 R1 (P/LONEOS) Feb 17.5 1.36 6.48 0 14.0 10.0 2001 T3 (NEAT) Jan 27.3 2.52 16 0 12.0 10.0 2001 T4 (NEAT) Jan 4.7 8.56 53 0 5.5 10.0 6P/d'Arrest Feb 3.6 1.35 6.53 17 10.0 20.0 7P/Pons-Winnecke May 15.7 1.26 6.38 21 10.0 15.0 15P/Finlay Feb 7.2 1.03 6.75 12 12.0 10.0 18D/Perrine-Mrkos Sep 10 1.29 6.76 5 11.5 20.0 22P/Kopff Dec 12.1 1.58 6.46 14 6.6 12.5 26P/Grigg-Skjellerup Nov 29.7 1.12 5.31 18 12.0 40.0 28P/Neujmin 1 Dec 27.4 1.55 18.2 5 8.5 15.0 30P/Reinmuth 1 Dec 24.4 1.88 7.32 9 9.5 15.0 31P/Schwassmann-Wachmann 2 Jan 18.4 3.41 8.72 11 6.7 11.3 39P/Oterma Dec 22.2 5.47 19.5 3 5.0 15.0 46P/Wirtanen Aug 27.0 1.06 5.44 8 9.0 15.0 54P/de Vico-Swift Aug 7.5 2.15 7.32 3 10.0 15.0 57P/du Toit-Neujmin-Delporte Jul 31.2 1.73 6.42 5 12.5 15.0 67P/Churymov-Gerasimenko Aug 18.3 1.29 6.57 5 9.5 10.0 77P/Longmore Sep 4.7 2.31 6.83 4 7.0 20.0 89P/Russell 2 Mar 23.0 2.29 7.42 3 10.0 15.0 90P/Gehrels 1 Jun 23.0 2.97 14.8 2 8.5 15.0 92P/Sanguin Sep 23.1 1.81 12.4 2 12.0 15.0 96P/Machholz 1 Jan 8.6 0.12 5.23 3 13.0 12.0 115P/Maury Dec 23.9 2.04 8.79 2 11.5 15.0 124P/Mrkos Jul 27.0 1.47 5.74 2 13.1 15.0 125P/Spacewatch Jan 28.1 1.53 5.54 2 15.5 10.0 P/Shoemaker 3 Dec 15.0 1.81 17.1 1 10.5 10.0 P/Helin-Lawrence Dec 22.4 3.11 9.52 1 10.0 10.0
The date of perihelion (T), perihelion distance (q), period (P), the number of previously observed returns (N) and the magnitude parameters H1 and K1 are given for each comet.
Note: m1 = H1 + 5.0 * log(d) + K1 * log(r)
BAA COMET SECTION NEWSLETTER 2001 October 7
The orbit of 96P/Machholz 1. is Mexico, as a small diffuse 10m beginning of the year fading from very unusual, with the smallest object on August 28.41 using a around 13th magnitude. perihelion distance of any short 0.40-m reflector x55. This was period comet (0.13 AU), which is his fourth discovery and his Several other comets return to decreasing further with time, a second periodic one. The comet perihelion during 2002, however high eccentricity (0.96) and a is in a Jupiter crossing orbit, but they are unlikely to become bright high inclination (60°). Studies by has not approached the planet for enough to observe visually or are Sekanina suggest it has only one several revolutions. At a poorly placed. 6P/d’Arrest, active area, which is situated favourable return it could reach 15P/Finlay, 26P/Grigg-Skjellerup close to the rotation pole and 7m. and 28P/Neujmin 2 have becomes active close to unfavourable returns. perihelion. The comet may be the It will be too far south for viewing 30P/Reinmuth 1, parent of the Quadrantid meteor from the UK when it gets into 31P/Schwassmann-Wachmann 2, shower. It is rarely sufficiently visual range in June. It reaches 39P/Oterma, 54P/de Vico-Swift, well placed to see visually and opposition in August when it may 57P/du Toit-Neujmin-Delporte, this return is no exception. be 12th magnitude and continues 77P/Longmore, 89P/Russell 2, However, at perihelion on 2002 to brighten. We may pick it up in 90P/Gehrels 1, 92P/Sanguin, January 8 it is only a few degrees November as it brightens to 10th 115P/Maury, 124P/Mrkos, from the Sun and may be seen in magnitude and we will be able to 125P/Spacewatch, 1999 F1 the SOHO LASCO coronagraphs follow it into the New Year as it (Catalina), 2001 C2 (LINEAR), from January 5 to 11. continues to move north. It is an 2001 K5 (LINEAR) and 2001 R1 evening object, but its solar (P/LONEOS) are intrinsically 116P/Wild 4 was discovered on elongation decreases from 80º in faint or distant comets. 1990 January 21.98 by Paul Wild November to 50º at the end of the Ephemerides for these can be with the 0.40-m Schmidt at the year. It will not reach perihelion found on the CBAT WWW pages. Zimmerwald station of the Berne until 2003. By October it is 18D/Perrine-Mrkos has not been Astronomical Institute at a moving north-eastwards in seen since 1968. photographic magnitude of 13.5. Capricornus and ends the year in At its brightest the comet only Aquarius. Looking ahead, 2003 has a good reached 12m, but it was return of 2P/Encke, which might surprisingly well observed. The Several recently discovered be observable from September comet was perturbed into its parabolic comets will be visible until the end of the year, when it present orbit after a close during 2002. 2000 SV74 could be 6th magnitude. This may approach to Jupiter in mid 1987. (LINEAR) will be fading from however be optimistic as 13th magnitude and may remain observations from the SOHO The comet emerges from the solar visible until December. 2000 spacecraft in 2000 showed that it glare in November, moving WM1 (LINEAR) begins the year suddenly brightened after south-eastwards in Virgo, but is too far south to be visible from the perihelion, which does not occur poorly placed for viewing from UK, but it is well placed for until late December 2003. the UK. It brightens from 13th Southern Hemisphere observers magnitude near the end of the and may be a binocular object. In References and sources year to 12th magnitude in April as March it will have moved far it nears opposition but is a long enough north for UK observation Nakano, S. and Green D. W. E., way south and will be difficult to and should still be a binocular Eds, International Comet observe from the UK. It is at object as it emerges into the Quarterly 2002 Comet Handbook, perihelion in January 2003. morning sky in Sagittarius. It (2001). continues to move rapidly north Shanklin, J. D., Observing Guide P/Shoemaker 3 (1986 A1) is also and will probably be best for to Comets, 2nd edition (2001) making its first return since northern viewers in mid month Marsden, B. G. Catalogue of discovery. It will be quite faint, when the moon is out of the sky. Cometary Orbits, 13th edition, around 14-13th magnitude, when It passes from Aquila into IAU CBAT, (1999). it is picked up in November and Hercules in April and will Kronk, G. W., Cometographia, does not get much brighter by the probably be too faint for easy Cambridge University Press, time it reaches opposition in observation by June. 2001 N2 (1999). February 2003. It moves (LINEAR) may reach 13th Belyaev, N. A., Kresak, L., eastwards from Cancer into Leo magnitude between May and Pittich, E. M. and Pushkarev, A. at the end of the year. August. 2001 HT50 (LINEAR) N., Catalogue of short Period will become visible towards the Comets, Bratislava (1986). P/Brewington 2 (1992 Q1) end of the year as it brightens makes its first return since its towards its perihelion in mid Jonathan Shanklin discovery in 1992. It was 2003. 2001 MD7 (P/LINEAR) discovered by Howard J may be visible to Southern Brewington of Cloudcroft, New Hemisphere observers at the
Professional Tales
Many of the scientific magazines intended to help you find the ones the next issue so that everyone have articles about comets in you've missed. If you find others can look them up. them and this regular feature is let me know and I'll put them in
BAA COMET SECTION NEWSLETTER 8 THE COMET’S TALE
The following abstracts (some the camera now needs to point to Berlin), located in the centre of shortened further for publication) different positions 1,000 times a Berlin. Further information will are taken from the Cambridge night. The new system captures be provided in the second Conference Network (CCNet), about 3.75 square degrees of the announcement, and on the web which is a scholarly electronic sky per image, hundreds of square page http://earn.dlr.de/ACM2002 network devoted to catastrophism, degrees per night, and most of the but which includes much accessible sky each month. information on comets. To LIGHTCURVE & COLOURS subscribe, contact the moderator The new NEAT camera takes OF UNUSUAL MINOR Benny J Peiser at pictures with 48 million pixels, PLANET 1998 WU24 Davies
Review of comet observations for 2001 April - 2001 October
The information in this report is a missed. The solar elongation is synopsis of material gleaned from only slowly increasing, but the IAU circulars 7606 – 7739 and comet moves north, although The Astronomer (2001 April – remaining a morning object. 2001 September). Note that the Slowly fading as it passes through figures quoted here are rounded the Leos (October) and into Ursa off from their original published Major (November), the comet accuracy. Lightcurves for the begins to move north more brighter comets are from rapidly and ends the year at 11m observations submitted to The in Canes Venatici. It begins 2002 Astronomer and the Director. A at 11m moving northward in full report of the comets seen Canes Venatici. It remains quite during the year will be published well placed as it fades, passing in the Journal in due course. into Ursa Major in late February when it is 12th magnitude. Comet 19P/Borrelly This is the comet's 13th observed return, with two poor ones having been BAA COMET SECTION NEWSLETTER 14 THE COMET’S TALE
19P/Borrelly drawn by Gabriel Comet 24P/Schaumasse The Comet 44P/Reinmuth has been comet peaked in brightness in late image by Giovanni Sostero in Oksa on August 29. th th April at around 11 magnitude. October at around 16 magnitude. The comet was first picked up by The uncorrected preliminary light Michael Mattiazzo, who curve from 78 observations is m = estimated it at 13th mag in mid 7.7 + 5 log d + 29.2 log r June. By July 22 it had brightened to 11.4, a bit fainter than expected. Observing on August 28.11 with my 0.20-m SCT x75 I made it 10.3, DC4, diameter 1.7'. It reached a peak of around 10th magnitude in September, shortly after perihelion, and is now slowly fading. The spacecraft Deep Space 1 successfully imaged the comet on September 22. The 44P/Reinmuth on October 22. uncorrected preliminary light curve from 43 observations is m = Comet 45P/Honda-Mrkos- 6.8 + 5 log d + 19.2 log r Pajdusakova made its 10th 24P/Schaumasse imaged by observed return since discovery in Rolando Ligustri on May 19. 1948 (it was missed in 1959). On Apr. 4.42 UT, K. Kadota, Ageo, Comet 29P/Schwassmann- Saitama, Japan, reported m_1 = Wachmann 1 This annual comet 10.5 and coma diameter 0'.8 has frequent outbursts and over (0.18-m reflector + CCD. [IAUC the past couple of years seems to 7608, 2001 April 9] Gabriel be more often active than not, Oksa reported a visual though it rarely gets brighter than observation on April 17.8, when 12m. It is possible that its pattern he estimated the comet at 9.3 in a of behaviour is changing. The 0.15m R x60, coma 2.5' diameter, randomly spaced outbursts may be DC4. The uncorrected due to a thermal heat wave preliminary light curve from 22 propagating into the nucleus and observations is m = 11.0 + 5 log d triggering sublimation of CO + 11.1 log r inside the comet. The comet was noted in outburst in June, July and August. The comet will be observable in Libra for the rest of the year, though it is not well placed for observing from the UK. This comet is an ideal target for those equipped with CCDs and it should be observed at every opportunity.
29P/Schwassmann-Wachmann 1 imaged by Rolando Ligustri and the CAST team on August 15. 45P/ drawn by Gabriel Oksa on April 17.
BAA COMET SECTION NEWSLETTER 2001 October 15
51P/Harrington has been imaged by a few CCD observers, who show it as well condensed with a faint tail.
51P/Harrington imaged by Rolando Ligustri on September 1999 T1 McNaught-Hartley On 24. April 24 I estimated it at around 12th mag in the Thorrowgood Comet 74P/Smirnova-Chernykh refractor. It continued to fade and was at perihelion in January became quite diffuse. The 2001. The uncorrected, rather uncorrected preliminary light unlikely, preliminary light curve curve from 419 observations is m from 27 observations is m = -9.8 = 6.3 + 5 log d + 9.4 log r + 5 log d + 38.4 log r
1999 T2 imaged by Rafael Ferrando on April 30.
1999 U4 Catalina-Skiff The object is very distant, but the extrapolated light curve suggests that it should be visible until mid 2002, fading from 13th mag. Pepe Manteca imaged the comet 74P/Smirnova-Chernykh imaged on August 25. The uncorrected preliminary light curve from 49 by Nick James on April 24. observations is m = 1.0 + 5 log d + 12.7 log r
1999 T1 imaged by Rolando
1999 J2 Skiff The comet is at Ligustri on May 12. high northern declination, and is 1999 Y1 LINEAR The comet is very distant at over 7 AU, with 1999 T2 LINEAR On 2001 April now beginning to fade and is a perihelion in October 1999. It 24 I was able to see the comet southern hemisphere object. Pepe will remain near 15th mag for clearly in the Northumberland Manteca imaged the comet on some time. The uncorrected refractor, estimating it at 13.5. several times in August. Michael preliminary light curve from 93 Observations are generally quite Mattiazzo has been following it observations is m = -1.2 + 5 log d scattered. The uncorrected from the Southern Hemisphere. + 13.4 log r preliminary light curve from 151 The uncorrected preliminary light observations is m = 6.5 + 5 log d curve from 120 observations is m + 8.2 log r = 6.4 + 5 log d + 7.6 log r
BAA COMET SECTION NEWSLETTER 16 THE COMET’S TALE
2000 WM1 imaged by Giovanni Sostero and colleagues from the Visnjan observatory in Croatia on August 8.
Montage of 6 comets imaged by Pepe Manteca on August 16/17 2000 CT54 LINEAR Yet another apparently asteroidal LINEAR 2000 WM1 LINEAR Brian object, of 19th mag, discovered on Marsden notes on MPEC 2001- February 2.44. Reinder Bouma M50 [2001 June 28] that 'The made a few observations in June th "original" and "future" when it was 14 mag. barycentric values of 1/a are
+0.000516 and -0.000250 (+/- 2000 WM1 imaged by the CAST 2000 OF8 Spacewatch The 0.000010) AU**-1, respectively.' comet reached perihelion in The original value is greater than team on September 9. August 2001 at 2.2 AU. An 10E-04, hence the comet is improved hyperbolic orbit probably not a new arrival from published on MPEC 2001-H34 the Oort cloud and has made at [2001 April 24] gives 1/a (orig) as least one previous visit to the 0.000047, showing that the comet inner solar system. The corrected is a new one from the Oort cloud. preliminary light curve from 76 Reinder Bouma estimated it th CCD and visual observations is m around 14 mag in June. = 6.5 + 5 log d + 9.7 log r, which predicts a peak magnitude in the 2000 SV74 The extrapolated light range 4 - 7. The comet does not curve suggests that the comet will reach perihelion until January slowly fade from 13th magnitude. 2002. It will be too far south at As with many comets the visual perihelion, but will return to observations generally put the northern skies and will then be comet as being brighter than CCD visible until August 2002. observations. The uncorrected preliminary light curve from 26 Comet 2000 WM1 (LINEAR) observations is m = 8.0 + 5 log d 3 + 4.1 log r. 4 2000 WM1 imaged by the CAST 5 6 team on October 22. 7 8 9 Previously unnamed comets 10 11 The IAU Committee on Small 12 Bodies Nomenclature has agreed 13
Observed magnitude 14 upon the names for the following 15 five comets: C/2000 S3 16 17 (LONEOS); 150P/2000 WT_168 18 (LONEOS); C/2000 Y2 (Skiff); 19 JanFebMarAprMayJun Jul AugSepOctNovDecJanFebMarApr C/2001 G1 (LONEOS); C/2001 2001 - 2002 HT_50 (LINEAR-NEAT). [IAUC 7674, 2001 July 30]
SOHO Kreutz group comets 1996 A2 SOHO (IAUC 7718, September 17) 1996 B4 SOHO (IAUC 7726, 2001 October 3) 1996 B5 SOHO (IAUC 7730, 2001 October 9) 1996 L1 SOHO (IAUC 7606, 2001 April 2) 1996 R4 SOHO (IAUC 7730, 2001 October 9) 1997 K7 SOHO (IAUC 7646, 2001 June 20) 1997 M5 SOHO (IAUC 7606, 2001 April 2) 1997 W3 SOHO (IAUC 7650, 2001 June 23) 1998 V7 SOHO (IAUC 7612, 2001 April 23) 2001 G2 SOHO (IAUC 7613, 2001 April 25) 2001 G3 SOHO (IAUC 7613, 2001 April 25) 2001 H1 SOHO (IAUC 7613, 2001 April 25)
BAA COMET SECTION NEWSLETTER 2001 October 17
2001 H2 SOHO (IAUC 7613, 2001 April 25) line. Both components are highly 2001 H3 SOHO (IAUC 7613, 2001 April 25) condensed. Observations (with 2001 H4 SOHO (IAUC 7613, 2001 April 25) the same telescope) on Apr. 24.14 2001 H6 SOHO (IAUC 7631, 2001 May 23) show only a single nucleus. 2001 H7 SOHO (IAUC 7631, 2001 May 23) [IAUC 7616, 2001 May 1] 2001 J2 SOHO (IAUC 7631, 2001 May 23) Using the absolute astrometry for 2001 J3 SOHO (IAUC 7631, 2001 May 23) Apr. 30 (see IAUC 7616) and 2001 J4 SOHO (IAUC 7631, 2001 May 23) May 9 given on MPC 42656 2001 K2 SOHO (IAUC 7631, 2001 May 23) (where the western primary is 2001 K4 SOHO (IAUC 7634, 2001 May 28) labeled B and the eastern 2001 K6 SOHO (IAUC 7641, 2001 June 6) secondary is labeled A), Z. 2001 K7 SOHO (IAUC 7641, 2001 June 6) Sekanina, Jet Propulsion Image by Nick James on July 15 2001 K8 SOHO (IAUC 7641, 2001 June 6) Laboratory, obtained a separation 2001 K9 SOHO (IAUC 7642, 2001 June 8) time of Mar. 17 +/- 12 and an O. Schuetz, E. Jehin, X. Bonfils, 2001 L1 SOHO (IAUC 7642, 2001 June 8) acceleration of 7.1 +/- 2.4 (in H. Boehnhardt, K. Brooks, A. 2001 L2 SOHO (IAUC 7642, 2001 June 8) units of 10**-5 solar gravity). Delsanti, O. Hainaut, E. 2001 L3 SOHO (IAUC 7642, 2001 June 8) [IAUC 7625, 2001 May 15] Jourdeuil, P. Leisy, M. Sterzik, 2001 L4 SOHO (IAUC 7642, 2001 June 8) and E. Wenderoth, European 2001 L5 SOHO (IAUC 7646, 2001 June 20) Southern Observatory (ESO); J. 2001 L6 SOHO (IAUC 7646, 2001 June 20) Helbert, DLR, Berlin; G. 2001 L7 SOHO (IAUC 7646, 2001 June 20) Garradd, Loomberah, N.S.W.; F. 2001 L8 SOHO (IAUC 7646, 2001 June 20) Marchis, University of California 2001 L9 SOHO (IAUC 7646, 2001 June 20) at Berkeley; B. Stecklum, TLS- 2001 M2 SOHO (IAUC 7650, 2001 June 23) Tautenburg; and G. Tozzi, 2001 M3 SOHO (IAUC 7650, 2001 June 23) Osservatorio Astrofisico di 2001 M4 SOHO (IAUC 7650, 2001 June 23) Arcetri, report that an intensive 2001 M5 SOHO (IAUC 7650, 2001 June 23) high-resolution monitoring of the 2001 M6 SOHO (IAUC 7650, 2001 June 23) inner coma on June 16-21 2001 M7 SOHO (IAUC 7655, 2001 July 2) indicates that the comet continues 2001 M8 SOHO (IAUC 7655, 2001 July 2) to fragment. The images obtained 2001 M9 SOHO (IAUC 7655, 2001 July 2) at ESO (La Silla) in the thermal 2001 M11 SOHO (IAUC 7667, 2001 July 19) infrared with the 3.6-m telescope 2001 O1 SOHO (IAUC 7667, 2001 July 19) (+ TIMMI2, N band), and in the 2001 R3 SOHO (IAUC 7718, September 17) optical region with the 3.5-m 2001 R4 SOHO (IAUC 7718, September 17) New Technology Telescope (+ 2001 R5 SOHO (IAUC 7718, September 17) EMMI, R filter) and the 2001 S2 SOHO (IAUC 7730, 2001 October 9) ESO/MPG 2.2-m telescope (+ 2001 T2 SOHO (IAUC 77xx, 2001 ) and WFI, R filter), show faint several other comets not yet given companions drifting away from identities were discovered with the principal nucleus (B) in an the SOHO LASCO coronographs Photograph by Michael Mattiazzo approximately antisolar direction. and have not been observed on 2001 June 12 Analysis by Z. Sekanina, Jet elsewhere. They were sungrazing Propulsion Laboratory, shows that comets of the Kreutz group and Z. Sekanina, Jet Propulsion all the observations can be were not expected to survive Laboratory, writes: "Astrometric satisfied by three fragments, D, E, perihelion. offsets of component A from B and F. The analysis implies that reported between Apr. 30 and fragment D separated from B on 2001 A2 LINEAR The latest May 18 (IAUC 7616, 7625, 7627, June 3.5 +/- 1.8 with a differential orbit has 1/a (orig) of 0.001164, MPC 42656, MPEC 2001-K14) nongravitational deceleration of demonstrating that this is not the indicate that the splitting 17 units (of 10**-5 the solar first time that the comet has occurred on Mar. 29.9 +/- 1.6 UT attraction) and with an initial visited the inner solar system. (thus coinciding with the major velocity of 1.0 +/- 0.1 m/s Michael Mattiazzo points out that outburst) and that the (approximately normal to the the orbital plane crossing took companion's relative deceleration orbit plane); fragment E on June place around July 15-16th. This is 15.2 +/- 0.7 units of 10**-5 9.5 +/- 0.7 with a deceleration of should have enhanced the dust solar attraction. Assuming that 53 units and a velocity of 0.3 +/- tail in the solar and anti solar the separation of component C 0.1 m/s; and fragment F on June directions. (IAUC 7627) from B coincided 11.3 +/- 0.5 with a deceleration of with the outburst of May 11, the 102 units and a velocity of 0.8 +/- C. W. Hergenrother, M. single available offset suggests 0.2 m/s. These breakup events Chamberlain, and Y. that C is subjected to a apparently triggered another Chamberlain, Lunar and deceleration of approximately 40 major outburst (cf. IAUC 7630), Planetary Laboratory, University units of 10**-5 solar attraction. reported by visual observers to of Arizona, report that 60-s R- have peaked on June 12. band images of C/2001 A2 taken on Apr. 30.12 UT with the L. M. Woodney and D. G. Catalina 1.54-m reflector show a Schleicher, Lowell Observatory; double nucleus. The two and R. Greer, Wittenberg components are nearly equal in University, report narrowband gas brightness and 3".5 apart and and dust imaging of this comet: aligned precisely on an east-west "On June 29-30, the comet BAA COMET SECTION NEWSLETTER 18 THE COMET’S TALE displayed CN jet(s) symmetrical solar flux. No emission is detected about p.a. 250 deg. Three from Ar I at 104.8 and 106.7 nm successive arcs separated by and He I at 58.4 nm (in second approximately 12 000 km were order). We derive Q(Ar)
In the Northern Hemisphere, Giovanni Sostero recovered the comet on June 27. I picked it up on July 1.05 with 7x50B and estimated it at 5.3. It was an easy Spectral scan of the coma by object, well condensed and Maurice Gavin on July 23 diameter 11'. On July 10.9 it was 2001 A2 imaged by Martin an easy object in 8x30B of about P. D. Feldman, H. A. Weaver, Mobberley on 2001 July 23 mag 5.5, DC3 and diameter 12'. and E. B. Burgh, Johns Hopkins A further outburst took place on University, report observations of David Seargent reported a visual July 12, and on July 12.95 it was comet C/2001 A2 with the Far observation at 13.1 on March 14, just visible to the naked eye from Ultraviolet Spectroscopic a little brighter than expected. It central Cambridge. The comet is Explorer beginning July 12.58 UT brightened very rapidly and now fading quite rapidly and has and coinciding with the reached 8th mag by the end of the become very diffuse, making it a photometric event reported on month. It continued to brighten difficult object to pick out against IAUC 7679: "Spectra (range 91- and became more condensed as it the Milky Way background. 118 nm; spectral resolution 0.03 approached the sun. An estimate Observations in mid August put it nm) were obtained using the 30" by Andrew Pearce on April 20.51 at around 9th magnitude, DC 1 - x 30" aperture. Several new put it at 7.1 in 20x80B. Several 2 and around 6' diameter. cometary emissions were estimates on April 24 commented Observing on August 28.06 with identified, particularly the (0,0) that the comet had brightened my 0.20-m SCT x75 I made it bands of the CO Birge-Hopfield rapidly in the last 24 hours and 10.8, DC1 and diameter 2.3' systems (C-X and B-X) at 108.8 was now around 6.5. By the end and 115.1 nm, respectively; O I of April it had reached 6th mag, [(^1)D-(^1)D] at 115.2 nm; and but during early May the rate of three lines of the H_2 Lyman brightening has slowed system at 107.16, 111.86, and significantly, perhaps associated 116.68 nm, pumped by solar with the nuclear splitting Lyman-beta fluorescence. Also observed at the end of April. detected were O I multiplets at More rapid brightening resumed 98.9, 102.7, and 104.0 nm, and around May 10 and the comet several lines of the H I Lyman reached around 5th mag. An series. The rotational envelopes of obsevation from Michael the CO bands are resolved and Mattiazzo on May 17.42 put it at appear to consist of both cold and 5.2 in 7x50B with a tail at least warm components, the cold 1.6 degrees long; the comet was component accounting for 80 also visible to the naked eye. As percent of the flux and having a of May 21 it was still 5th mag. rotational temperature of 60 K. Andrew Pearce reported that the The warm component may be comet had brightened to 4.8 on The uncorrected preliminary light indicative of a CO_2 source. Both May 31.44 and the comet had a curve from 879 observations is m the CO bands and the O I 115.2- 1.5 degree long tail. The coma = 7.3 + 5 log d + 10.6 log r, with nm emission (an indicator of was noticeably blue-green in several small outbursts after the H_2O production) decreased by a colour. On June 11.91 Andrew major one at the end of March. factor of two over the 7.5 hr reported further brightening, One a week or so later and observation. Preliminary estimating the comet at 3.6 to the another in mid June. The light estimates of the production rates naked eye and a 1.7 degree long curve also suggests that there was at the beginning of the tail in 20x80B. Michael quasi- periodic variation in the observation are Q(CO) = 4 x Mattiazzo photographed the light curve with an amplitude of 10^(27) s^(-1) and Q(H_2O) = 3 comet on June 12. about a magnitude. x 10^(29) s^(-1) (vectorial model). These values may be 2001 H5 P/NEAT E. F. Helin, S. uncertain by as much as a factor Pravdo, and K. Lawrence, Jet of two, due to uncertainties in the Propulsion Laboratory, report the BAA COMET SECTION NEWSLETTER 2001 October 19 discovery of a 17th mag comet on M. Nelson with the 1.8-m f/1 region again on October 19. The April 24.35, on CCD images VATT Lennon telescope on May October 7 linkage is clearly taken with the 1.2-m Oschin 27 make it clear that the orbital correct, and this pins down the Schmidt telescope at Palomar in period is about 7.5-7.9 years. current period as 7.64 years. the course of the NEAT program. Spahr has also identified the CCD images taken on Apr. 25.0 comet with a very faint object (not Running this orbit back gives a UT by M. Tichy and M. Kocer at described as cometary) discovered moderately close approach to Klet (0.57-m f/5.2 reflector) show by A. E. Gleason with the Jupiter (0.8 AU) in 1972, before the diffuse object to have a coma Spacewatch telescope on 2000 which the P/2001 J1 perihelion diameter of 9". C. E. Lopez Oct. 7 and placed on The NEO distance was 0.96 AU and the reports that CCD observations Confirmation Page but removed inclination 11 degrees. While obtained on Apr. 25.2 at El on Oct. 20 for lack of follow-up. there was tolerably good Leoncito (0.5-m f/7.5 double The additional astrometry and agreement in orbital eccentricity, astrograph) also show the object orbital elements (P = 7.64 yr) are argument of perihelion and nodal to be diffuse. Additional given on MPEC 2001-K43. S. longitude, it is difficult to astrometry (including LINEAR Nakano has noted some rough reconcile the perihelion distance prediscovery observations on Mar. similarity to the orbit of comet and inclination with the 3D/Biela 20 identified by B. G. Marsden) 3D/Biela. [IAUC 7635, 2001 May values. To get these elements to and orbital elements (T = 2001 29] agree would require the Jan. 27.0 TT, q = 2.390 AU, i = nongravitational forces to act in 8.4 deg, P = 15.0 yr) are given on Brian Marsden has provided some some special way, together with MPEC 2001-H37. [IAUC 7613, additional information about this the gravitational effects of 2001 April 25] The comet will possibility: While I cannot occasional approaches to Jupiter. fade. exclude with 100-percent certainty the possibility that the Whether or not the comets are 2001 HT50 LINEAR-NEAT S. new comet P/2001 J1 (NEAT) is identical, why was the current Pravdo, E. Helin and K. the long-lost 3D/Biela, I really comet not observed earlier in the Lawrence, Jet Propulsion don't think it is. twentieth century? After all, the Laboratory, report the discovery perihelion distance of under 1 AU of a possible 18th mag comet by What, indeed, happened to does allow moderately close NEAT on CCD images obtained 3D/Biela after 1852? Did it break approaches to the earth--with a with the 1.2-m Schmidt at up completely? Some 30 years minimum orbital distance of Palomar on May 14.22. T. B. ago I looked into the possibility perhaps 0.15 AU and an actual Spahr, Minor Planet Center, has of finding that comet again and minimum distance of perhaps 0.5 identified the object with the published a number of different AU in 1955. Actually, it is quite apparently asteroidal object 2001 orbits based on different clear that at many passages HT50, observed by LINEAR on possibilities for the action of the through perihelion the small Apr. 23 and by LONEOS on Apr. nongravitational forces on the elongation from the sun would 26 (MPS 30375), and has now comet after 1852. For an epoch completely preclude observations, found observations back to Mar. around 1971 these orbits all had and by the time the object had 3. Further details and parabolic perihelion distances under 0.83 moved around to opposition it orbital elements (T = 2003 July 8, AU and inclinations to the would be as faint as when q = 2.80 AU, Peri = 324 deg, ecliptic under 8.1 degrees. Spacewatch fortuitously observed Node = 43 deg, Incl. = 163 deg, it last October. Even under the equinox 2000.0) are given on Coming now to the recent comet, more favorable circumstances of MPEC 2001-J31. [IAUC 7624, although unusually large the 1955 perihelion passage, the 2001 May 14] The comet could inconsistencies among the best one could hope for at a 90- reach 11th mag or brighter at its observations made it particularly degree elongation from the sun two oppositions in 2003. difficult to establish the orbit, and would be magnitude 15, and more given that the comet's position in typically (as this year), one would 2001 J1 NEAT S. Pravdo, E. the sky makes it difficult to have to contend with a maximum Helin, and K. Lawrence, Jet observe, I note that some careful elongation of 70-80 degrees and Propulsion Laboratory, report the observations on May 27 by Carl magnitude 16 if one were lucky. discovery of a 17th mag comet by Hergenrother and Tim Spahr with We _were_ lucky that NEAT was NEAT on CCD images taken the Vatican Advanced Technology observing this year so far from with the 1.2-m reflector at Telescope in Arizona isolated the opposition, and there would have Haleakala on May 11.25. The revolution period to 7.5-7.9 been no observing program with object appears diffuse also on years. Tim then realized that the the capability of making the confirming CCD observations object had in fact been reported discovery at the previous taken by L. Sarounova at as unusual--though not of comparable elongation in 1985. Ondrejov (coma diameter about cometary appearance--by Unless the comet is now 15") and by M. Tichy and J. Arianna Gleason at Spacewatch anomalously faint, that it escaped Ticha at Klet (coma diameter on October 7 last year. The prior detection is fully about 8"-10"). [IAUC 7623, 2001 object was then listed on The reasonable--a situation not a bit May 11] The comet is NEO Confirmation Page for like that of 3D/Biela on several intrinsically very faint. almost two weeks, although it was occasions in the late eighteenth obviously too faint for essentially and early nineteenth centuries. As hinted on IAUC 7625, this is a all of the likely follow-up short-period comet, and observers, and Spacewatch itself 2001 K1 P/NEAT S. Pravdo, E. observations by C. W. evidently just missed the comet's Helin and K. Lawrence, Jet Hergenrother, T. B. Spahr, and position when it recorded the Propulsion Laboratory, report the BAA COMET SECTION NEWSLETTER 20 THE COMET’S TALE discovery of a 19th mag comet by will remain at around 14th mag NEAT on CCD images taken visually for some time. This is with the 1.2-m reflector at LINEARs 64th comet. Haleakala on May 20.5 and 21.4 UT. M. Tichy and M. Kocer, Klet 2001 M1 P/Helin M. Busch, A. Observatory, note that the object Seib, F. Hormuth, and R. Stoss, had a 14" coma on May 21.9. P. Starkenburg- Sternwarte, Pravec and P. Kusnirak, Ondrejov Heppenheim; and A. Gnadig and Observatory, report a 0'.3 coma A. Doppler, Archenhold- and a 0'.8 tail in p.a. 290 deg on Sternwarte, Berlin, report the May 21.9. T. B. Spahr, Minor recovery of P/1987 Q3 (= 1987w Planet Center, has identified = 1987 XVII) on CCD images asteroidal observations of the taken by Busch, Seib, and object in LONEOS and LINEAR Hormuth with the EOCA 1.52-m data back to Feb. 2. Full details reflector at Calar Alto on June are on MPEC 2001-K17. [IAUC 20.14 at 20th magnitude. The 7629, 2001 May 21] The comet is indicated correction to the periodic and will fade. prediction by B. G. Marsden on 2001 MD7 imaged by the CAST MPC 31664 (ephemeris on MPC team on October 14. 2001 K3 Skiff B. A. Skiff, Lowell 42160) is Delta(T) = -1.0 day. Observatory, reports his discovery [IAUC 7648, 2001 June 21] The 2001 N1 SOHO Discovered by of a 16th mag comet on images comet will brighten a little. Xavier Leprette, the orbit for this taken with the LONEOS 0.59-m SOHO comet published on MPEC Schmidt on May 22.4; the coma 2001 M10 NEAT K. J. Lawrence, 2001-N24 [2001 July 11] is was well condensed, about 20" in E. F. Helin, and S. Pravdo, Jet substantially different from the diameter, and a tail extended Propulsion Laboratory, report the bulk of the Kreutz group about 60" in p.a. 225 deg. discovery by NEAT of a 19th mag members. Although the comet Following placement in The NEO comet on 2001 July 20.28 with has a similar perihelion distance Confirmation Page, further the Palomar 1.2-m Schmidt and to that of the Kreutz group, the observations were reported, and the Haleakala 1.2-m reflector on inclination, at 95 degrees, is far they are listed on MPEC 2001- June 29.58. [IAUC 7654, 2001 from the usual value of around K24, together with preliminary June 30] The comet is in a distant 144 degrees. This is SOHO's parabolic orbital elements (T = (q=5.3) orbit with a period of 138 340th comet. 2001 Jan. 12, q = 1.87 AU, Peri. years. M. D. Hicks, Jet = 315 deg, Node = 281 deg, Incl. Propulsion Laboratory, reports 2001 N2 LINEAR An apparently = 37 deg, equinox 2000.0). M. that this comet shows a diffuse asteroidal 18th mag object Tichy and M. Kocer (Klet, 0.57- coma of diameter about 5" and a reported by LINEAR on July m reflector) reported a compact faint tail about 7" long in p.a. 240 11.38, which was posted on the 8" coma; D. T. Durig (Sewanee, deg in a 10-min R-band CCD NEO Confirmation Page, has TN, 0.30-m reflector) a 30" tail; exposure obtained on June 30.3 been found to have a diffuse coma K. Smalley (Olathe, KS, 0.75-m UT with the 0.61-m reflector at and a faint 5" tail in p.a. about 90 reflector) a tail approximately 30 Table Mountain (observers D. deg in a 3 min r-band CCD deg wide, brightest along the Esqueda, Hicks, and T. Ha). exposure taken with the 0.6-m southern edge (p.a. about 210 Hicks' name also should be added reflector at Table Mountain by M. deg), where it extended for about to the list of NEAT team Hicks, D. Esqueda, and T. Ha. 2'; R. Dyvig (Quinn, SD, 0.66-m members on IAUC 7654. [IAUC [IAUC 7661, 2001 July 13] The reflector) a possible coma and 7655, 2001 July 2] comet reaches perihelion in faint tail in p.a. about 225 deg. August 2002 and could reach [IAUC 7631, 2001 May 23] 2001 MD7 P/LINEAR N. Blythe, 13th magnitude. Lincoln Laboratory Experimental 2001 K5 LINEAR A 17th mag Test System, reports the discovery 2001 O2 NEAT K. J. Lawrence, object reported as asteroidal by by LINEAR of an 17th mag S. Pravdo, and E. F. Helin, Jet the LINEAR program on May comet on images obtained on July Propulsion Laboratory, report the 17.28 (with prediscovery 11.22, when it appeared diffuse. discovery by NEAT of a diffuse LINEAR observations on Apr. 30 Subsequent observations 19th mag comet with some identified by G. V. Williams) and permitted identification with the central condensation on July posted on The NEO Confirmation object 2001 MD_7, so designated 25.42; on July 29, it showed Page has been found to be slightly on MPS 31852 as a result of nebulosity 12" toward the east. diffuse with coma diameter 8" on LINEAR observations made on [IAUC 7673, 2001 July 30] CCD images taken at Klet on June 21.31 and 24. L. Sarounova Regarding the announcement of May 27.0 UT by M. Tichy and J. reports that CCD images of the this comet on IAUC 7673, the Ticha and to be strongly comet obtained on July 12.9 UT observations on July 25 were condensed with a 12" coma and a at Ondrejov show a bright nucleus made at Haleakala, while those on 13" tail in p.a. 210 deg on 300-s and faint coma. [IAUC 7660, July 29 were made at Palomar. R-band exposures taken with the 2001 July 12] The comet could Additional astrometry and very 1.8-m f/1 Vatican Advanced reach 13th magnitude in the uncertain parabolic orbital Technology Telescope at Mt. autumn. This is LINEARs 65th elements (from 17 observations, Graham on May 27.3 by C. W. comet. Michael Mattiazzo July 25-Aug. 1) and an ephemeris Hergenrother, T. B. Spahr, and observed it on October 14 when it appear on MPEC 2001-P01. M. Nelson. [IAUC 7634, 2001 had brightened to 14.2 in his [IAUC 7676, 2001 August 1]. May 28] The comet is distant and 0.27-m SCT x88. BAA COMET SECTION NEWSLETTER 2001 October 21
The comet is a distant one, past surfaces typical of short-period 2001-P22 [2001 August 8] is perihelion and will fade. comet nuclei. substantially different from the bulk of the Kreutz group A/2001 OG108 (LONEOS) This However, 2001 OG108 is one of members. Although the comet has asteroid was discovered by the brightest Earth-crossing a similar perihelion distance to LONEOS on July 28.39 at 19th asteroids found so far. According that of the Kreutz group, the magnitude. It has a high to LONEOS director Ted Bowell, inclination, at 151 degrees, is far inclination cometary type orbit, just two other Earth-crossers from the usual value of around though no activity has so far been rival it in brightness. But 1866 144 degrees and the value of L is detected. With a period of 51 Sisyphus and 2000 WF129 orbit around 208. This is SOHO's years it doesn't reach its the sun in the inner solar system 343rd comet. perihelion of 1AU until March and are unlikely to be as 2002, when it may reach 14th intrinsically dark as 2001 2001 P2 SOHO Discovered by magnitude at high northern OG108, Bowell says. If the newly Sebastian Hoenig, the orbit for declination. If it does show any discovered asteroid is darker and this SOHO comet published on cometary activity it may well be reflects less light than Sisyphus MPEC 2001-Q02 [2001 August brighter than this. Details of the and 2000 WF129, but appears 16] is substantially different from observations and orbit were given just as bright, it must be larger. the bulk of the Kreutz group on MPEC 2001-P40 on August members. Although the comet has 13. Based on its brightness, its a similar perihelion distance to current distance, and an that of the Kreutz group, the Large Earth-Crossing Asteroid expectation of its albedo, Bowell inclination, at 130 degrees, is far Found. A newly discovered rare estimates that 2001 OG108 could from the usual value of around asteroid may be the largest be as large as 10 miles (15 144 degrees and the value of L is Earth-crosser known. Vanessa kilometers). The median size of around 220 degrees. This is Thomas, Astronomy.com, 24 the approximately 800 known SOHO's 344th comet. August 2001 Earth-crossing asteroids is less than one kilometer, so "this 2001 P3 39P/Oterma Y. R. During the past decade, object really sticks out," he says. Fernandez, University of Hawaii, astronomers have begun finding reports his recovery of comet 39P members of an unusual breed of Although 2001 OG108 will on CCD frames obtained on Aug. asteroids. Called Damocloids occasionally zip past Earth 13.42 at 22nd mag with the 2.2-m after the first of their kind during its 50-year journey about University of Hawaii reflector, discovered, 5335 Damocles, these the sun, Bowell assures that confirmatory images being asteroids have elliptical orbits Earthlings need not worry that obtained on Aug. 20 and 21 by K. that resemble those of short- the asteroid will impact Earth - at J. Meech and J. Pittichova. The period comets like Comet Halley. least not in the near future. In its object, a point source, was located A new member of this strange present orbit, the Damocloid will about 2' from the prediction by B. astronomical club has now been not come any closer to us than G. Marsden on MPC 34423 found, and its brightness suggests about 28 million miles (about 45 (ephemeris on MPC 42373). that it might be the largest Earth- million kilometers), or more than Meech then succeeded in locating crossing asteroid known. 100 times the distance between the comet on her CCD frames Earth and its moon. The from 1999 May 9 and July 15. M. Provisionally titled 2001 OG108, astronomer points out, however, A. Kadooka and J. M. Bauer the object was first spotted on that the asteroid could potentially assisted, and the measurements by July 28 by Michael Van Ness, an pass within 100 million miles of Meech are given on MPEC 2001- observer for the Lowell Jupiter, which may result in an Q35. The recovery also confirms Observatory Near-Earth-Object orbital adjustment by the giant the correctness of positions Search (LONEOS) program in planet's gravitational tentatively measured by G. V. Arizona. Over the next two weeks, manipulation. Williams from images obtained observers tracked the newfound by D. C. Jewitt, J. X. Luu, and C. asteroid to determine its path Currently passing through the A. Trujillo on 1998 May 1 and about the sun. Like other main asteroid belt toward the 22. MPEC 2001-Q35 also Damocloids, 2001 OG108 has an inner solar system, 2001 OG108 includes orbital elements from elongated orbit. Each trip about will make its next close approach 227 observations (1942-2001) and the sun takes it from beyond to Earth in April of next year. As a revised ephemeris. Last Uranus to just within Earth's it zooms past Polaris in our observed in Aug. 1962, comet orbital path. northern skies, the asteroid will 39P passed 0.095 AU from be bright enough for amateur Jupiter on 1963 Apr. 12, after Because Damocloids mimic the astronomers to spot with which q increased from 3.4 to 5.5 course of short-period comets, moderately sized telescopes. AU and P from 7.9 to 19 years astronomers suspect these unique Professional astronomers will (with T = 1983 June 18 and 2002 asteroids might actually be likely take interest in this rare Dec. 22). [IAUC 7689, 2001 "dead" comets. While the gas and space rock as well, in order to August 24] ices that cause comets to flare up study its composition and attempt when they approach the sun may to confirm its once-cometary A/2001 PT13 This is a distant have been exhausted, the dark, nature. asteroid, with perihelion at 8.5 rocky remains continue to travel AU in 1999 February, with a through the solar system. If this 2001 P1 SOHO Discovered by period of 35 years. notion is correct, these asteroids Tony Scarmato, the orbit for this should have the same dark SOHO comet published on MPEC BAA COMET SECTION NEWSLETTER 22 THE COMET’S TALE
2001 Q1 NEAT K. J. Lawrence, eyepiece. Thinking it might be a E. F. Helin, and S. Pravdo, Jet galaxy, he looked at his star Propulsion Laboratory, report the charts to see if any were nearby, discovery by the Near Earth but there was no galaxy in the Asteroid Tracking program of a vicinity. new 19th mag comet on CCD images obtained with the 1.2-m Petriew announced his comet Oschin Schmidt telescope at discovery hours later, and since Palomar on August 17.20 then astronomers have been Lawrence notes that the object is monitoring the newfound comet to diffuse with a nuclear learn more about it. Based on condensation of diameter about data spanning less that a week, it 3". Following posting on the NEO appears that Comet Petriew may Confirmation Page, P. Pravec and be travelling around the Sun once P. Kusnirak (Ondrejov 0.65-m every 5.5 years following an reflector) confirmed its cometary elliptical path that stretches from appearance on CCD images a point just inside Earth's orbit obtained on Aug. 18.9 UT, and 2001 Q2 drawn by Gabriel Oksa (0.95 AU) out to the realm of the M. Kocer (Klet 0.57-m reflector) on August 29. giant planet Jupiter (5.3 AU). reports that the object is diffuse and at m_1 = 18.0 on Aug. 18.9. The following is taken from the Says Brian Marsden of the T. B. Spahr, Minor Planet Center, SPA ENB 2001 August 27 : In Smithsonian Institution's Minor has also identified the object in centuries past astronomers Planet Center: "We're still not data obtained by LONEOS on discovered new comets the old- completely sure of the orbital July 16.2. Full astrometry and fashioned way: they peered period, but Comet Petriew might parabolic orbital elements appear through telescopes or simply have passed close to Jupiter in on MPEC 2001-Q18. [IAUC looked toward the sky, hunting for 1982 -- an encounter that could 7685, 2001 August 18]. The faint smudges that no one had have nudged the comet into its comet is distant and will not get seen before. It was hard work, but current orbit." Before 1982 any brighter. lots of people did it. Comets are Comet Petriew's orbit was named after their discoverers, probably bigger than it is now. It 2001 Q2 P/Petriew Vance Avery after all, and finding a new one couldn't have come so close to Petriew, Regina, SK, reported his can mean instant fame. Hale- Earth in decades past, which visual discovery of an 11th mag Bopp, Hyakutake and Shoemaker- might explain why it was never comet with a round coma of Levy are just a few of the names spotted before. diameter 3' and condensed we know ... because of comets. nucleus and no tail during a star party at Cypress Hills But lately it seems just about Interprovincial Park, every new comet is called Saskatchewan on August 18.42 "LINEAR" or "NEAT." Those are using a 0.51-m f/5 reflector at names, too, but not the names of 80x. The object's presence was humans. They're robots -- also confirmed visually by R. automated, computer controlled Huziak (0.25-m reflector) and P. telescopes that scan the skies in a Campbell (0.32-m reflector) at relentless search for near-Earth Cypress Hills. [IAUC 7686, 2001 asteroids and comets. This year August 19] Additional astrometry between January and mid-August and orbital elements by B. G. such telescopes recorded 18 new Marsden, Smithsonian comets, while humans had found Astrophysical Observatory, none. Comet hunters -- the human appear on MPEC 2001-Q31. The kind -- just can't compete! At eccentricity is very uncertain, and least that's how many the orbit indicates a close beleaguered sky watchers have approach to Jupiter in 1982. S. been feeling. But now Canadian 2001 Q2 imaged by Pepe Nakano, Sumoto, Japan, has also amateur astronomer Vance Manteca on August 21. computed an elliptical orbit and Petriew has proved humans can notes the similarity to the orbit of still discover a comet the old- The comet was a relatively easy comet 103P. [IAUC 7688, 2001 fashioned way. object in the morning sky. August 21] The ephemeris Observing on August 27.12 with suggests that the comet should Petriew was at the Saskatchewan 20cm T x75 I made it 10.1, DC3 have been within visual range Summer Star Party on August and 1.6' diameter, and in since July, which suggests that 18th when he turned his 20" 14x100B it was 9.3, DC3 and 4.7' either the comet has recently telescope toward the Crab diameter. An observation in mid outburst (or has a steep light Nebula. Hopping from one star to September suggested that it had curve) or that the morning sky is another across the constellation changed little in brightness, not being well patrolled by Taurus, Petriew guided his however it is now fading and is amateur comet hunters. telescope toward the famous likely to be fainter than 13th supernova remnant -- but he magnitude by the end of October. never made it. He stopped instead The uncorrected preliminary light at a curious smudge that curve from 30 observations is m = appeared unexpectedly in his 10.8 + 5 log d + 20.3 log r BAA COMET SECTION NEWSLETTER 2001 October 23
which are considerably in error. image on Aug. 28.41 shows a Magnitude parameters are also central nebulosity of diameter extremely uncertain. At the about 3" and a tail about 10" long moment they suggest an object of toward the west-southwest. Other perhaps 0 magnitude in early reported physical descriptions May, though as it brightens it is from CCD images include: Aug. at high southern declination. 28.98 UT, diffuse (M. Tichy, Perihelion a little earlier than Klet, 0.57-m reflector); 29.05, given by the elements would give diffuse object (m_1 = 16.4) with a a potentially spectacular object in bright nucleus, m_2 = 17.9 (L. April 2004, whereas a month Sarounova and M. Wolf, later the apparition would be Ondrejov, 0.65-m reflector); fairly average. 29.38, coma diameter about 10" (K. Smalley, Louisburg, KS, 0.75- 2001 Q5 P/LINEAR-NEAT K. J. m reflector); 29.44, well- Lawrence, E. F. Helin, and S. H. condensed coma, broad tail 15" Pravdo, Jet Propulsion long in p.a. 240 deg (D. Balam, 2001 Q3 SOHO This non Kreutz Laboratory, reported the discovery Dominion Astrophysical comet was discovered by Chen by the NEAT program of a comet, Observatory, 1.82-m Plaskett Hua Dong on SOHO imagery on of 17th mag, having a nuclear telescope); 29.47, fuzzy with a August 25. Further to IAUC condensation of diameter about 6" hint of a bulge to the southwest 7689, D. Hammer reports and a 100" tail toward the (P. J. Shelus, McDonald astrometric measurements of a southwest, on CCD images taken Observatory, 0.76-m reflector). comet found by Chen Dong Hua with the 1.2-m Schmidt telescope Additional astrometry and on SOHO website images. The at Palomar on Aug. 28.35. preliminary parabolic orbital object was first detected on Following posting on the NEO elements (from 25 observations, August 25.34 at mag 8.3 in Confirmation Page, T. B. Spahr Aug. 28-29) appear on MPEC LASCO C2 coronagraph images, (Minor Planet Center) identified 2001-Q70. [IAUC 7698, 2001 moving southward from directly this object with an object reported August 29] Initial observations underneath the occulter; the as asteroidal by the LINEAR suggested that the comet could comet brightened and showed a program (first detected on Aug. reach 14th mag at high northern nice tail before entering the C3 17.40 at m_2 = 18.6-19.4). Other declination in October, however it field-of-view, where it began to reported physical descriptions was unexpectedly a couple of fade, as indicated by the following from CCD images include: Aug. magnitudes brighter. This is additional V magnitudes provided 29.04 UT, m_1 = 16.0, tail 50" NEAT's 15th comet and their by D. Biesecker and Hammer: long in p.a. 237 deg (M. Tichy, 13th this year. Aug. 25.393 UT, 7.6; 25.463, 7.4; Klet, 0.57-m reflector); 29.05, 25.977, 5.7; 26.102, 4.8; 26.221, small coma, tail at least 4' long 5.2; 26.227, 4.6; 26.446, 5.8; (L. Sarounova, Ondrejov, 0.65-m 26.811, 8.0. [IAUC 7694, 2001 reflector); 29.08, diffuse (A. August 28] Galad and D. Kalmancok, Modra, 0.6-m reflector); 29.30, 40" tail in 2001 Q4 NEAT S. H. Pravdo, E. p.a. 243 deg (K. Smalley, F. Helin, and K. J. Lawrence, Jet Louisburg, KS, 0.75-m reflector); Propulsion Laboratory, report the 29.38, well-condensed coma, discovery of a 20th mag comet on broad tail 2' long in p.a. 246 deg CCD images taken on August (D. Balam, Dominion 24.40 with the 1.2-m Schmidt Astrophysical Observatory, 1.82- telescope at Palomar in the course m Plaskett telescope); 29.43, m_1 of the NEAT program; their = 16.9, tail about 70" long in p.a. images on Aug. 24, 26, and 27 about 240 deg (P. J. Shelus, show a spherically symmetrical McDonald Observatory, 0.76-m nebulosity with diameter about 8". reflector). Additional astrometry CCD total magnitude estimates: and orbital elements by B. G. Aug. 27.08 UT, 17.8 (J. Ticha, Marsden (from 35 observations, M. Tichy, and P. Jelinek, Klet Aug. 17-29) appear on MPEC P/2001 Q6 imaged by Nick James Observatory, 0.57-m reflector); 2001-Q69 [IAUC 7697, 2001 on October 23. Aug. 27.47, 17.3 (P. J. Shelus, August 29] The comet was at McDonald Observatory, 0.76-m perihelion in June and will not 2001 Q7 SOHO A non Kreutz reflector). [IAUC 7695, 2001 get significantly brighter. It has a object of 8th magnitude August 28] The comet was period of 6.6 years. This is discovered by R Kracht on C2 discovered when still over 10 AU LINEAR's 65th comet. images on August 21. from the Sun. 2001 Q6 NEAT S. H. Pravdo, E. A/2001 QF6 (LINEAR) The elements on MPC 43604 give F. Helin, and K. J. Lawrence, Jet Discovered by LINEAR on T as mid May 2004, with q of Propulsion Laboratory, report the August 16.27, this 19th mag 0.96 AU. The uncertainty in the discovery of another comet, of asteroid has a 23 year period, elements is greater than the 18th mag on CCD images taken with perihelion at 2.2 AU. It will precision to which they are given with the 1.2-m Schmidt telescope reach perihelion in February so extrapolation of the comet's at Palomar in the course of the 2002. position could lead to predictions NEAT program; their discovery BAA COMET SECTION NEWSLETTER 24 THE COMET’S TALE
A/2001 QL169 (NEAT) LINEAR on Sept. 10.32 and 11 and P. Kusnirak at Ondrejov Discovered by NEAT on August showed that this object, (moderately condensed coma of 17.47, this 20th mag asteroid has designated 2001 RX_14 on MPS diameter 0'.2 on Oct. 14.9 UT) a 5.5 year period, with perihelion 34978, had a nearly parabolic and by J. Ticha, M. Tichy, and P. at 1.53 AU and is just past orbit. After placement on the Jelinek at Klet (diffuse 11" coma perihelion. The orbit is typical of NEO Confirmation Page, many on Oct. 14.9; 10" coma and m_1 a short period comet and makes further observations were = 17.0 on Oct. 15.8). [IAUC close approaches to Jupiter. The received, with M. Tichy (Klet, 7733, 2001 October 15] The orbit is not significantly changed 0.57-m f/5.2 reflector + CCD) on comet is in a 16 year periodic by approaches in 1860 (0.74 AU), Oct. 18.7 UT indicating that the orbit with perihelion at 2.5 AU. It 1943 (0.74 AU), 2014 (0.78 AU) comet appeared to be diffuse with will fade. and 2098 (0.84 AU). [MPEC a coma of diameter 13" and red 2001-R05, 2001 September 1] mag 16.7. R-band images taken 2001 T4 NEAT S. Pravdo, E. F. by C. Hergenrother and J. Barnes Helin, M. Hicks, and K. 2001 R1 P/LONEOS An (Lunar and Planetary Laboratory) Lawrence, Jet Propulsion apparently asteroidal 18th mag with the 1.54-m Catalina reflector Laboratory, report the discovery (red) object discovered by on Oct. 24.32 show a highly by the NEAT program of a 20th LONEOS on September 10.19 condensed coma of diameter 6" mag comet with a diffuse coma of and posted on the NEO and no hint of a tail. [IAUC 7739, diameter about 4" and a Confirmation Page has been 2001 October 26] The comet southward tail about 10" long on found cometary. It has a period reaches perihelion at 2.06 AU in CCD images taken on Oct. 15.35 of 7.89 years and will be at January 2003 and could reach 10th with the Palomar 1.2-m Schmidt perihelion on 2002 January 30. magnitude. It will come within telescope. Additional NEAT [IAUC 7713, 2001 September 11] visual range in August 2002. images on Oct. 21.4 UT show the It will brighten a little, but will comet as very diffuse and faint, not come within visual range. 2001 S1 Skiff B. Skiff, Lowell elongated east-west. The comet Improved orbital elements by B. Observatory, reports his discovery has a perihelion distance of 8.6 G. Marsden were published on of an apparent 20th mag comet on AU and a period of 53 years. MPEC 2001-S05, including LONEOS telescope images [IAUC 7738, 2001 October 23] prediscovery observations on obtained on Sept. 26.4 UT, when Aug. 19 by LINEAR and these the object appeared distinctly less A/2001 TD45 (LINEAR) is indicate that this comet will pass well concentrated than nearby another faint asteroid of 20th only 0.014 AU from Mars on stars (despite poor seeing), with magnitude, discovered by 2002 Jan. 10.7 TT, as first an apparent 17" coma. LINEAR on October 15.40. It's suggested by C.-I. Lagerkvist Observations by R. H. McNaught 0.72 year orbit takes it to within (Uppsala) and G. Hahn (German at Siding Spring on Sept. 26 show 0.17 AU of the Sun at perihelion Aerospace Center, Berlin). [IAUC a coma barely different from the and out to the orbit of Mars at 7720, 2001 September 19] 2"-3" seeing but with a short tail aphelion. (< 10" long) in p.a. about 40 deg. 2001 R6 P/LINEAR-Skiff B. A. J. G. Ries reports that CCD A/2001 TX16 (LINEAR) is an Skiff, Lowell Observatory, reports images obtained with the 0.76-m asteroid, of 17th magnitude, his discovery of a 17th mag comet reflector at McDonald discovered by LINEAR on on CCD images taken by him Observatory on Sept. 28.4 October 13. With a period of with the LONEOS telescope on confirm the northeastward tail of 6.77 years, the orbit is typical of a Sept. 25.32. The object shows a length about 10". [IAUC 7725, Jupiter family comet. There were moderately condensed 15" coma 2001 September 29] The comet is approaches to Jupiter of 0.80 AU and a broad tail about 25" toward distant and past perihelion and in 1985 and 0.73 AU in 1937. No the west-northwest. T. B. Spahr will fade. observer has reported this object identified this comet with an to have cometary appearance. object observed on two nights A/2001 SS287 (LINEAR) A 19th [MPEC 2001-U45, 2001 October (Sept. 11 and 16, previously mag asteroid discovered by 25] It reaches perihelion at 1.44 linked; m_2 = 19.4-20.0) and LINEAR on September 27.41 has AU in January, so may yet show reported as asteroidal in a perihelion distance of 1.07 AU cometary activity. appearance by LINEAR; and a period of 6.13 in a typical subsequently LINEAR Jupiter family comet orbit. A/2001 UO16 (LINEAR) is an observations from Aug. 19 were Perihelion is due on Oct. 20.75. asteroid, of 19th magnitude, also identified. J. G. Ries reports discovered by LINEAR on that CCD images obtained with 2001 T1 SOHO A non Kreutz October 21.26. With a period of the 0.76-m reflector at McDonald object discovered by Xavier 6.13 years, the orbit is typical of a Observatory on Sept. 27.3 UT Leprette on C2 images on Oct. 9. Jupiter family comet. It was at also show this object to be diffuse. perihelion at the beginning of [IAUC 7723, 2001 September 27] 2001 T3 P/NEAT K. Lawrence, October. The comet has a period of 8.3 S. Pravdo, and E. F. Helin, Jet years and a perihelion distance of Propulsion Laboratory, report the For the latest information on 2.1 AU. discovery on October 14.45 by the discoveries and the brightness of NEAT program of an 18th mag comets see the Section www page: 2001 RX14 LINEAR The comet with a faint coma on CCD http://www.ast.cam.ac.uk/~jds linkage by the Minor Planet images taken with the Palomar or the CBAT headlines page at Center of subsequent observations 1.2-m Schmidt telescope. The http://cfa-www.harvard.edu/ of an apparent 19th mag main- object also appears cometary on cfa/ps/Headlines.html belt minor planet observed by CCD images taken by P. Pravec BAA COMET SECTION NEWSLETTER 2001 October 25
BAA COMET SECTION NEWSLETTER 26 THE COMET’S TALE
BAA COMET SECTION NEWSLETTER