Copyright © 1993-2000 by the California Institute of Technology
In the course of the Second Palomar Observatory Sky Survey, the 48-inch Oschin Schmidt Telescope at Palomar Observatory (California, USA) accidently photographed this comet on 1990 December 19.11. The comet trailed during the exposure of the Kodak IIIaF (red) plate. This image was obtained through SkyMorph at the Goddard Space Flight Center.
This comet was discovered by Henry E. Holt and C. Michelle Olmstead (Palomar Observatory, California, USA) on photographic plates exposed on 1990 September 14 and 17, with the 0.46-m Schmidt telescope. They determined the magnitude as 17.2. The comet was then located in Pisces. The comet was also found on plates obtained on September 16 using the same telescope and the magnitude was determined as 17.0.
The comet was first announced on 1990 September 18. By September 21 enough positions had become available for Brian G. Marsden (Central Bureau for Astronomical Telegrams) to compute a short-period orbit. He found a perihelion date of 1990 September 28, a perihelion distance of 2.04 AU, and an orbital period of 6.20 years. The comet was followed until December 14. After all of the positions had become available the orbit was refined to indicate a perihelion date of October 4.5, a perihelion distance of 2.043 AU, and an orbital period of 6.16 years.
Marsden integrated the orbit of the comet forward and predicted the next return to perihelion would occur on 1997 February 6.68, which was not a favorable apparition. James V. Scotti (Kitt Peak, Arizona, USA) recovered it on 1996 September 19 and 20. He said the comet was essentially stellar with a slight hint of diffuseness. The six available CCD images indicated a magnitude ranging from 20.1 to 20.6. The precise positions indicated the prediction required a correction of only -0.02 day, which is excellent considering the prediction was based on less than three months of observations. Scotti's final position on September 20.23 was the last observation of this apparition. Astronomers at Mauna Kea found three prerecovery images from 1996 June 16, while astronomers at Whipple Observatory (Mt. Hopkins) found two prerecovery images from September 19.