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Reports from Geisei Observatory<October 28, 2002>


• 72P/Denning-Fujikawa
This comet has not been observed since 1978. Checking my record I found that Mr. Hirohisa Sato had sent me its O-C(the difference between observed values and predicted values). To my surprise, of all the data 40% was those by Geisei Observatory, which lacked accuracy. The total number of observations in 1978 was only 25. In those days there were far fewer observers and this situation had continued until 10 years ago. Why did they lack accuracy? Soon after Mr. Fujikawa discovered the comet by his 16cm reflector in October 1978, I observed it with my 12cm binoculars. Its total magnitude was about 10.5. It was diffuse and fuzzy like a patch of fog. It was just like C/2002 O4 (Hoenig) immediately before its extinction. In the 40cm reflector it was not easy to determine the center. It might have been the last appearance before it disappeared.I attempted to observe this comet under favorable conditions by the 60cm reflector in 1986 when Halley's comet returned. In those days I often used Fuji FLO-II(glass plate), Kodak 103aE, and Fuji w-ray film, but there was no image of this comet captured on them.At the moment I am searching for 18D/Perrine-Mrkos, which has not been recovered since 1969. I have taken about 50 shots within ± 30 days according to Mr. Kenji Muraoka's predictions. Once it is recovered, I may be able to find it on old film. From November I will start a visual search along with photographic search by the 21cm telescope. The comet may be too diffuse and extensive to capture on film.






Copyright (C) 2002 Tsutomu Seki.