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.^[5]

65P/Gunn

Infrared image of Gunn's Comet taken from the WISE observatory on 11 June 2010
Discovery
Discovered by	James E. Gunn
Discovery site	Palomar Observatory
Discovery date	17 October 1970
Designations
MPC designation	P/1954 P1 P/1970 U2
Alternative designations	1953 VIII, 1969 II 1976 III, 1989 XI 1970p
Orbital characteristics[1][2]
Epoch	17 October 2024 (JD 2460600.5)
Observation arc	46.67 years
Earliest precovery date	8 August 1954[3]
Number of observations	7,963
Aphelion	4.737 AU
Perihelion	1.597 AU
Semi-major axis	3.453 AU
Eccentricity	0.3194
Orbital period	6.414 years
Inclination	3.237°
Longitude of ascending node	136.09°
Argument of periapsis	41.568°
Mean anomaly	103.17°
Last perihelion	16 October 2017[4]
Next perihelion	16 June 2025
TJupiter	2.991
Earth MOID	1.903 AU
Jupiter MOID	0.396 AU
Physical characteristics[1]
Dimensions	10.8 km (6.7 mi)
Comet total magnitude (M1)	10.1

Observational history

It was discovered on 11 October 1970 by Professor James E. Gunn of Princeton University using the 122-cm Schmidt telescope at the Palomar Observatory. It had a low brightness of magnitude 16, which improves to 12 under favourable conditions. In 1972 Elizabeth Roemer managed to observe 65P/Gunn close to aphelion.^[6]

On 4 February 1970 the comet passed 0.015 AU (2.2 million km; 1.4 million mi) from Ceres.

In 1980 it was noticed that a 19th magnitude comet found in plates obtained by Palomar Observatory on 8 August 1954^[3] was a previous apparition of 65/Gunn. The link was confirmed by Brian G. Marsden.^[7]

See also

• List of numbered comets