Copyright © 1997 by Akimasa Nakamura (Kuma Kogen Astronomical Observatory, Japan)
This CCD image was taken on 1997 May 31.7, using a 0.60-m f/6.0 Ritchey-Chretien telescope.
Paul Wild (Astronomical Institute, Berne University, Switzerland) on 1990 January 21.98 at a position of RA=9h 34m 31.69s, DEC=+20° 39' 39.5" (1950.0). He described the comet as strongly condensed, with a total magnitude of 13.5-14.0. There was a fan-shaped tail extending about one arc minute toward the northwest.
B. G. Marsden (Central Bureau for Astronomical Telegrams) announced on IAU Circular 4956 (dated 1990 January 31) that the comet's orbit was of short period. He used 15 positions obtained during the period of 1990 January 21-26 and determined the perihelion date as 1990 July 4, the perihelion distance as 1.950 AU, and the orbital period as 6.25 years.
A later revised orbit by Wild indicated the comet passed close to Jupiter during 1987 July. The result was the semimajor axis changing from 4.6 to 3.4 and the eccentricity changing from 0.17 to 0.41.
The comet's maximum magnitude was consistently estimated as about 12. Because of the large perihelion distance, this value remained virtually unchanged from about late February until late April 1990.
The comet's second appearance began on 1994 November 9.4, when it was recovered by J. V. Scotti (Lunar and Planetary Laboratory, Arizona, USA). The comet's image was then indistinguishable from that of a star and Scotti estimated the magnitude as 20.4-20.7. The position indicated the predicted orbit needed a correction of -0.3 day. The comet steadily brightened as it approached its 1996 August 31 perihelion date. By the beginning of 1996 it was already brighter than magnitude 13. By summer it had reached a maximum brightness of 12, and then began a slow fading thereafter. The comet reached a minimum solar elongation of only 40' on October 30.
The comet next passed perihelion on 2003 January 21 and came within 1.29 AU of Earth during the first days of May of 2003. The comet was brightest during the period of April into early June, when the total magnitude was typically estimated within the range of 11.5 to 12. The coma was then 1-1.5 arc minute across.