Copyright © 1997 by Akimasa Nakamura (Kuma Kogen Astronomical Observatory, Japan)
This is the recovery image obtained by Nakamura on 1997 April 29, using a 0.60-m f/6 Ritchey-Chretien telescope.
Robert H. McNaught discovered this comet on a plate exposed 1991 September 30.51 with the U. K. Schmidt telescope by Shaun M. Hughes at Siding Spring. The comet's brightness was estimated as magnitude 16.5. The comet was described as strongly condensed and it exhibited a diffuse tail extending 2 arc minutes toward PA 250 degrees. McNaught confirmed the discovery on October 1.46 when the comet was photographed with the Uppsala Southern Schmidt telescope.
Following the acquisition of images up through 1991 October 5, Daniel W. E. Green (Central Bureau for Astronomical Telegrams) computed the first orbit which inicated the comet was moving in a short-period orbit. Although this orbit was preliminary, Green determined the perihelion date as 1991 June 29.2, the perihelion distance as 2.173 AU, and the orbital period as 6.82 years. Green revised his orbit on October 24, after receiving positions obtained up through October 12. The resulting perihelion date was 1991 June 16.32, the perihelion distance was 2.125 AU, and the orbital period was 6.70.
This comet was independently recovered by J. V. Scotti (Lunar and Planetary Laboratory, Arizona, USA) and Akimasa Nakamura (Kuma Kogen Astronomical Observatory) during 1997 April. Scotti found the comet on images obtained with the 0.9-m Spacewatch telescope on Kitt Peak. The images were obtained on April 16.45, 16.47, and 16.49. The total magnitude was estimated as 20.6 on the first two images and 20.1 on the last image. Nakamura detected the comet on images obtained with a 0.60-m Richey Chretien telescope on April 29.66, 29.67, and 29.68. Nakamura said the comet appeared stellar and had a total magnitude of 20.3. The precise positions indicated the predicted perihelion date required a correction of +0.02 day.
The comet last passed perihelion on 1998 February 23.76. It reached a maximum magnitude near 18.5 near the final months of 1998.