Copyright © 2006 by Ramón Naves (Montcabrer Observatory)
This image was obtained by R. Naves on 2006 February 25.97.
This comet was discovered at the Purple Mountain Observatory on 1965 January 11.84, moving slowly through Cancer. The magnitude was estimated as 15. An additional observation was obtained on January 13.85.
Astronomers at the Purple Mountain Observatory computed the first orbit which was first published on March 4. It was an elliptical orbit indicating a perihelion date of 1965 February 9.72 and an orbital period of 6.69 years. Later orbits computed after all the observations had been collected indicated the perihelion date was February 9.29 and the period was 6.79. In 1975 Grzegorz Sitarski said the orbit indicated the comet approached to within 0.4592 AU from Jupiter on 1962 January 3.039 and that the previous orbital period had been 6.93 years.
The comet remained a relatively faint object during its discovery apparition. It was followed until 1965 May 31, at which time Elizabeth Roemer determined the nuclear magnitude as 19.1.
Sitarski computed a revised elliptical orbit for this comet during 1968 and predicted the comet would next arrive at perihelion on 1971 November 28.92. Roemer (University of Arizona, USA) recovered this comet with the 154-cm reflector at Catalina on September 19.48, 1971. She determined the magnitude as 19.7, and described the comet as quite condensed, with a possible trace of tail to the northwest. The positions indicated the prediction by Sitarski needed a correction of +0.97 day. As with the discovery apparition, the comet's maximum magnitude attained 15.
The comet was again seen in 1978, 1985, 1991-1992, and 1998-1999. It continues to remain a faint object as a result of its 1.8 AU perihelion distance. It was seen for just over a month in 1978, a little less than a month during 1985, and was just shy of two months during the 1991-1992 apparition. The 1998-1999 apparition was the best during this period, with the comet remaining visible for over 6 months and becoming slightly brighter than magnitude 15.
APPARITION OF 1999
[Perihelion Date=1999 March 8.18; Period=6.79 years]
K. Muraoka took positions from the period of 1965-1992, included full planetary perturbations, and solved for nongravitational effects. He predicted the comet would next pass perihelion on 1999 March 8.18.