Copyright © 1997 by James V. Scotti (The Spacewatch Project, Arizona)
This image was obtained on 1997 December 31. Scotti used the 0.9-m Spacewatch telescope and a CCD camera. The image is 4.5 arc minutes across, with north at the top and west to the right.
Quentin A. Parker and Malcolm Hartley (Siding Spring Observatory, Australia) discovered images of this comet on a plate taken by Parker on 1989 March 2.54 with the 1.2-m U.K. Schmidt Telescope. The comet appeared as a condensed object of magnitude 16.5 and it exhibited a tail extending six arc minutes toward PA 295 degrees.
Shortly after the comet's announcement, R. H. McNaught (Siding Spring) found a weak, diffuse trail on a plate exposed by Parker on February 11.63, and a short time after that, McNaught proved that the February and March objects were the same comet.
It was quickly realized that this comet had passed perihelion nearly two years prior to its discovery and astronomers began looking for other images of the comet. On March 7 it was announced that S. Nakano had identified minor planet 1986 TF with the comet. A. Mrkos (Klet) and P. Jensen (Brorfelde) had both reported this as a minor planet and an orbit had been determined which indicated it was a Hilda-class minor planet. The new observations allowed a very precise determination of the orbit just 5 days after its initial discovery. Jensen reexamined his images of 1986 TF and found they were slightly diffuse when compared to other minor planets on the same plate.
McNaught computed the first orbit for this comet shortly after finding the February prediscovery image. This orbit indicated the comet was a short-period comet. The perihelion date was determined as 1987 May 26, the perihelion distance was 3.09 AU, and the orbital period was 8.33 years. The orbit indicated the comet probably passed close to Jupiter during 1983.
After Nakano's linking the comet to "minor planet" 1986 TF, he computed a very precise orbit which gave the perihelion date as 1987 August 15.6, the perihelion distance as 3.025 AU, and the orbital period as 8.885 years. Nakano also revealed the comet had passed 0.17 AU from Jupiter in 1984 and the prior to this it had a perihelion distance of 4.4. AU.
The comet was recovered by James V. Scotti (Spacewatch, Arizona, USA) on 1995 June 23.43. The precise position indicated the predicted perihelion needed a correction of only +0.7 day. The comet's nucleus was then magnitude 20.5, while the total magnitude was 19.2. The coma was seven arc seconds across and a tail extended 0.88 arc minute toward PA 247 degrees.
The comet last passed perihelion on 1996 June 24.
Copyright © 1997 by Herman Mikuz (Crni Vrh Observatory, Slovenia)
This image was obtained on 1997 January 30.873 UT (start). Mikuz used a 36-cm, f/6.8 S-C telescope, V-filter and CCD. Exposure time was 5 minutes. The magnitude was then about 16.7, while the coma diameter was 0.5 arc minute. (Image reversed by Author)
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 1986 October 9.26. The comet trailed during the exposure of the Kodak IIIaF (red) plate. This image was obtained through SkyMorph at the Goddard Space Flight Center.