THE COMET’S TALE Newsletter of the Comet Section of the British Astronomical Association Volume 4, No 2 (Issue 8), 1997 November The Search for Comet P/Pons-Gambart Andreas Kammerer, Ettlingen, Germany It was an article by Alex Vincent Adolphe Gambart in Marseille, with the latter having a higher in the newsletter of BAA's Comet France independently discovered intrinsic magnitude. However, Section which drew my attention a comet in the constellation with the help of a search to the then "lost" comets de Vico Cassiopeia. They did not make ephemeris it should be possible to and Pons-Gambart. The author any remarks concerning the find this comet too, even in the predicted the return of these brightness, but it seems that the case of the worst perihelion comets for 1997-1999 and 1999- comet was of magnitude 5 to 6. circumstances. These occur in the 2000, respectively. As is known, The comet steadily grew fainter case the comet reaches perihelion comet de Vico was rediscovered and the last observation already in winter, with the comet never in September, 1995, reaching 5 came on July 21 with an assumed getting brighter than 8-9 mag and mag and displaying a very brightness of about 8 mag. being situated uncomfortably for dynamic ion tail. Three years Northerners. In contrast, a before another "lost" periodical First calculations assumed a perihelion date in mid-August comet, Swift-Tuttle, was parabolic orbit with perihelion will bring it close to the earth rediscovered as it approached the date on June 8. But in 1917 Ogura (minimum distance: 0.16 A.U.), sun, again observed by thousands showed that the comet really was with the comet perhaps as bright of people, although the of short period. He calculated two as 3-4 mag (Fig. 1). circumstances were as bad as they different periods of either 46 or could be, with the comet at 64 years. In 1978 S. Nakano perihelion nearly on the opposite reinvestigated the apparition of side of the sun. Most astronomers this comet and found a period of had anticipated this mother comet 57.5 +/- 10 years. All these of the Perseids 12 years in calculations confirmed however, advance. However, the orbit was that the comet was hopelessly not well determined and an lost. Since 1827 it should have investigation by Brian Marsden reached perihelion twice, but was even showed a possible identity not observed. with comet Kegler in 1737, leading to his prediction of a Then in 1979 I. Hasegawa found probable perihelion date at the an interesting link. While end of 1992. Several weeks investigating Chinese records of Continued on page 4 before this date the comet was ancient comets he noted that a rediscovered heading towards the comet in 1110 had a very similar sun. orbit to that of comet Pons- Gambart. More recently Kenji Contents Now there is the possibility of Muraoka determined a current rediscovering just another "lost" orbital period of 56.15 years and Comet Section contacts 2 comet within the next few years. proposed the likely return to Section news 2 Because comet Pons-Gambart perihelion for December 5, 1997. Section meeting 3 was observed for only one month However, it has to be pointed out Comet Pons-Gambart (cont) 3 its period too can only be that his investigation still has an Natural Catastrophes 6 determined with an uncertainty of uncertainty of several years. Letters 8 several years. Tales from the Past 9 As a result, the circumstances for Professional Tales 9 Details about the apparition are rediscovering comet Pons- Review of observations 10 poor: On June 21, 1827 Jean Gambart are not any better than Prospects for 1998 13 Louis Pons in Florence, Italy and they were for comet Swift-Tuttle - 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 251400 (W) Fax: (+44) (0)1223 362616 (W) 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] or [email protected] Photographic Advisor: Michael Hendrie, Overbury, 33 Lexden Road, West Bergholt, COLCHESTER, Essex, CO6 3BX, England Phone: (+44) (0)1206 240021 Section news from the Director Dear Section member, Doherty who was a long standing Getliffe, Guus Gilein, Bjoern cometary observer. You will all Granslo, Roberto Haver, Andreas Thankfully no new bright comets have heard of the death of Gene Kammerer, Graham Keitch, Heinz have been discovered, so I have Shoemaker; he will be sadly Kerner, Mark Kidger, Atilla been able to catch up a little on missed. Dr Jurgen Rahe, a Kosa-Kiss, Martin Lehky, Section work, though pressure on leading NASA astronomer, was Romualdo Lourencon, Herman my time has meant that this killed when a tree fell on his car Mikuz, John O’Neil, Andrew newsletter is a little later than during a severe storm near his Pearce, Oddleiv Skilbrei, Josep intended. A paper on the comets home of Potomac, MD. He had Trigo, Vince Tuboly, Graham of 1993 has been accepted for the been a co-leader of the Wolf, Seiichi Yoshida and Journal and I’ve made good International Halley Watch and Vittorio Zanotta (apologies for progress on the comets of 1994. was also involved with the Giotto, any omissions or miss- Despite requesting an Clementine, Rosetta and NEAR classifications). improvement in reporting missions. standards in the last newsletter, Comets under observation were: the majority of observers are still Since the last newsletter 2P/Encke, 29P/Schwassmann- making mistakes in reporting their observations or contributions Wachmann 1, 43P/Wolf- observations to Guy. This greatly have been received from the Harrington, 46P/Wirtanen, increases the workload for Guy, following BAA members: 48P/Johnson, 78P/Gehrels 2, so please try and submit 81P/Wild 2, 103P/Hartley 2, observations exactly in TA or James Abott, Mark Armstrong, C/Hale-Bopp (1995 O1), ICQ format if you are submitting Sally Beaumont, Denis C/Evans-Drinkwater (1996 J1), by e-mail, or use the Section Buczynski, Emilio Colombo, Eric C/Mueller (1997 D1), C/Mueller report forms if submitting by post. Dinham, Mike Gainsford, (1997 J1), C/Meunier-Dupouy We will give a further briefing on Massimo Giuntoli, Werner (1997 J2), C/Tabur (1997 N1), submitting observations at the Hasubick, Mike Hendrie, Colin C/Tilbrook (1997 O1) and Section meeting in February. Henshaw, Guy Hurst, Nick James, C//Utsunomiya (1997 T1). This meeting will concentrate on Albert Jones, Norman Kiernan, observational techniques and how John Mackey, Glyn Marsh, You will see a few changes to the to report observations, though Richard McKim, Haldun Menali, format of the ephemerides in the there will be time for a few Martin Mobberley, Stewart observing supplement. I now general talks as well. See the Moore, Bob Neville, Detlev give positions for both B1950 and details on page ?. Niechoy, Brian O'Halloran, J2000 epochs, and the times are in Gabriel Oksa, John Rogers, UT. I’ve increased the interval Several deaths have occurred in Jonathan Shanklin, Tony Tanti, between positions to 5 days for the last six months. Stan Melvyn Taylor and Alex Vincent. the fainter comets and those not Milbourn, a former Section visible from the UK. Let me Director died in August. A full and also from: Jose Aguiar, know if you like these changes obituary will appear in the Journal Cornel Apetroaei, Alexandr and if there is anything else you’d in due course. I have also just Baransky, Sandro Baroni, John like to see in the Newsletter. I learnt of the death of Paul Bortle, Reinder Bouma, Haakon look forward to seeing as many of Dahle, Alfons Diepvens, Stephen BAA COMET SECTION NEWSLETTER 1997 NOVEMBER 3 you as possible at the Section meeting. Jonathan Shanklin BAA COMET SECTION NEWSLETTER 4 THE COMET’S TALE Provisional Meeting Programme Observing Techniques Saturday, February 14 Institute of Astronomy, Cambridge 10:30 Doors open, refreshments available 11:15 Tour of RGO and Observatories 12:15 Lunch 13:30 Jon Shanklin Introduction 13:35 Jon Shanklin Visual Observing 14:05 Guy Hurst Reporting Observations 14:30 Mike Irwin Discovering Kuiper Belt Objects 15:00 Members slot 15:15 Tea 15:45 Nick James Comet image processing 16:15 Bob Neville Determining CCD comet magnitudes 16:45 TBA CCD astrometry 17:30 Observing if clear There is an entry charge of £1.00 to cover administration costs, tea, coffee and biscuits. A buffet lunch is available for £4.00 if you book in advance – please send bookings to me. The Churchill is just down the road and there are a couple of good pubs in Coton, about a mile away. If you would like to speak please let me know. Some exhibition space is available and recent observations will be on display. If you would like to exhibit material, please let me know in advance. There will be stands by the BAA, CAA, CUAS and TA. The TA special supplement on Hale-Bopp and the CD ROM will be available for purchase. The meeting will take place in the Hoyle building of the Institute of Astronomy.