International Comet Quarterly

The IWCAs and their predecessors, the American Workshops on Cometary Astronomy (four AWCAs were held in the United States between 1982 and 1987), were established by the ICQ as a forum for bringing amateur and professional astronomers together with the goals of (1) improving the acquisition of cometary information, (2) increasing understanding as to what science can be gained through observing comets by both amateurs and professionals, and (3) providing a forum in which cometary astronomers can meet others from distant geographical locations and discuss various issues. This concept was continued for IWCA I (held in February 1994 in Selvino, Italy). The following report was published on pages 30-31 of the April 1994 issue of the International Comet Quarterly (vol. 16; whole no. 90).

INTERNATIONAL WORKSHOP ON COMETARY ASTRONOMY

The first International Workshop on Cometary Astronomy (IWCA) was held on 1994 February 18 and 19 in Selvino, Italy, with about 40 people attending from 11 different countries. Those travelling the furthest distances to the meeting were Charles S. Morris from southern California and Akimasa Nakamura from Shikoku, Japan.

The host organizing committee did a fabulous job in selecting a scenic setting in the Italian "pre-Alps" that included a most comfortable hotel and a very good meeting site half a block from the hotel. The meeting had been expanded to two days from the original single day, due to high pre-registration numbers, and discussion of the meeting afterwards by attendants yielded agreement that future meetings should consider three days. In fact, it was announced that the second IWCA will probably be held in mid-August 1999 in Cambridge, England, during the week after the total solar eclipse that crosses central Europe; Jonathan Shanklin, who heads the Comets Section of the British Astronomical Association, is eager to host IWCA II at that time, and we hope to have comet enthusiasts from many more countries attending that meeting (because so many are likely to be drawn to Europe to view the solar eclipse). An early suggestion is to hold the meeting from Saturday through Monday, August 14-16 (the eclipse occurs on Wednesday, August 11).

There was widespread interest in Selvino to have a published Proceedings from the meeting, and these were later published in the ICQ.

On Friday morning, I talked about the ICQ archive and what we have accomplished thus far. Jonathan Shanklin of Cambridge, England, talked about his work on archival observations from the British Astronomical Association's Comets Section files, much of the work occuring during his annual travels to Antarctica by ship, during his work with the British Antarctic Survey. Akimasa Nakamura then talked about comet discovery from Japan.

After lunch on Friday afternoon, John E. Bortle of Stormville, New York, talked about drawing comet features, and Mauro Vittorio Zanotta of Milano, Italy, spoke about his comet-hunting techniques; he had hunted 220 hours before finding comet 1991g_1, and also made independent discoveries of P/Metcalf-Brewington and Tsuchiya-Kiuchi 1990i. ICQ Associate Editor Charles S. Morris of La Canada, California, talked about studies of P/Halley in trying to relate the total visual magnitude to gas- and dust-production rates determined from specific bandpass spectrophotometry. Akos Kerestzuri of Budapest, Hungary, spoke briefly about the Hungarian Astronomical Association, whose Comet Section was formed in 1991. Giuseppe Canonaco of Genk, Belgium, talked about the comet section of the VVS in Belgium. Capping off the Friday session, Stephane Garro talked about the current status of observing in France.

On Saturday morning, Andreas Kammerer talked about the German group of comet observers, and more specifically about an approach that he has developed concerning the prediction of visual tail lengths of comets, based on about 2500 observations of tail lengths taken from the ICQ archive. Jose Carvajal Martinez and Fran Garcia of Madrid, Spain, spoke about activities by Spanish observers; Carvajal agreed to become the ICQ Observation Coordinator for his country, effective immediately. Herman Mikuz of Ljubljana, Slovenia, talked about his extensive CCD imaging and photometry of comets and showed numerous interesting slides of his results. E. Peter Bus of The Netherlands showed amazing processed images of the inner coma detail in P/Swift-Tuttle (taken with the 1-m reflector of Dany Cardoen at Puimichel, France, during Nov. 29-Dec. 20) on the screens of two lap-top computers; many jets and fountains are visible on the 6' x 8' exposures that ranged from 120 seconds on the first night to only 1 second on Dec. 18.

On Saturday afternoon, Bortle and Morris conducted an open forum for about two hours on visual comet observing techniques. They began by showing five drawings of various "hypothetical" comets and asked all of the observers at the meeting to privately judge the degree of condensation (DC) and to hand in their DC estimates on paper for statistical tabulation by Shanklin, which was shown to the group later in the afternoon; the discussion surrounding this test was quite enthusiastic and interesting, and details will be presented in the published proceedings of the IWCA. (More extensive indoor testing with pre-drawn comet images will be offered at the IWCA II in 1999.) Further talks included that by Andrea Boattini of Firenze, Italy, who recounted the finding of his pre-recovery images of P/Swift-Tuttle on photographs taken with the 40-cm Asiago telescope in January 1992, and that by Bernd Brinkmann from Germany, who showed about 20 slides from Hoher List Observatory. Antonio Milani spoke about the Italian comet section, which was founded in 1976, and Alex Scholten talked about the Dutch Comet Section.

We thank the Unione Astrofili Italiani, the Circolo Astrofili Bergamaschi, the ICQ and Smithsonian Astrophysical Observatory, and Sky and Telescope magazine for providing funding to help make this first IWCA a huge success. -- D. W. E. Green