65P/Gunn

65P/Gunn is a periodic comet in the Solar System orbiting the Sun every 6.41 years inside the main asteroid belt between the orbits of the planets Mars and Jupiter.

Observational history

It was discovered on 11 October 1970 by James E. Gunn of Princeton University using the 122-cm Schmidt telescope at the Palomar Observatory. It had a low brightness of magnitude 16 at that time. In 1972, Elizabeth Roemer managed to observe 65P/Gunn close to aphelion.
In 1980, it was noticed that a 19th magnitude comet found in plates obtained by Palomar Observatory on 8 August 1954 was a previous apparition of 65P/Gunn. The link was confirmed by Toshiro Nomura and Brian G. Marsden.
During the very favorable apparition of 1996, 65P/Gunn reached magnitude 12.

Orbit

On 4 February 1970, the comet passed from Ceres.

Physical characteristics

Infrared observations from the IRAS satellite in 1983 detected a dust trail around 65P/Gunn, indicating that it had a mass loss rate of kg/s. Additional observations from the Infrared Space Observatory in 1996 revealed a strongly asymmetric dust trail, with a higher mass loss rate of 100–300 kg/s by November 1996.
CCD photometry conducted between 1993 and 1996 reveal a nucleus that is less than in diameter, later revised to. The comet was very active when it was observed, therefore the size estimate likely represent an upper limit.