Perihelion date: 7 February 2022
Perihelion distance (q): 2.3
Aphelion distance (Q) : 4.9
Period (years): 6.8
Eccentricity (e): 0.37
Inclination (i): 15.5
JPL orbit diagram
Paul Wild (Astronomical Institute, Berne University, Switzerland) discovered this
comet on exposures obtained with the 0.4-m Schmidt telescope at Zimmerwald. The
photographic plates were exposed on 11-12 April 1980. He estimated the magnitude
as 15.5 and added that the comet was diffuse with a rather strong condensation.
Since nearly a month had passed since the images were exposed, Wild made an
attempt to recover it. The comet was found on a plate exposed on 7 May. The
brightness and appearance were unchanged since the April observations.
Both Wild and Brian G. Marsden determined the comet was moving in a short-period
orbit. Marsden's calculations were first published on 9 May and revealed a perihelion
date of 6 October 1980, a perihelion distance of 2.296 AU, and an orbital period of
6.90 years. Further observations did aid in refining the orbit, but Marsden's
computations were very close because of the nearly one-month observational arc.
Marsden initially noted that the comet passed 0.13 AU from Jupiter during August
1976. Prior to this encounter the perihelion distance had been 4.2 AU and the orbital
period was 10.3 years. The comet was moving toward the sun and away from Earth
at the time of its discovery. Subsequently its brightness changed little. It was last
detected on 11 August 1980, at which time the magnitude was estimated as 16.
T. Gehrels and J. V. Scotti (Lunar and Planetary Laboratory, University of Arizona,
USA) recovered the comet on 29 January 1987 with the 0.91-m Spacewatch
telescope. The total magnitude was then given as 19.5, while the diffuse coma was 14
arc seconds across. The comet was kept under observation until 11 September 1988,
at which time the magnitude of the nuclear condensation was given as 21.
The comet was next expected to pass perihelion on 21 July 1994. Scotti and Gehrels
recovered it with the 0.91-m Spacewatch telescope on 10 February 1994. The
magnitude was given as between 20.7 and 21.2. The coma was then 12 arc seconds
across and there was a tail extending 0.29 arc minute toward PA 292°. The magnitude
of the nuclear condensation was determined as 22.3. The precise positions indicated
the prediction required a correction of only +0.03 day. The comet was followed until
30 December 1997.
Observations (VEMag = visual equivalent magnitude)