77P/Longmore is a Jupiter-family comet with a 6.9-year orbit around the Sun. It is the only comet discovered by Australian astronomer, Andrew Jonathan Longmore.
Observational history It was discovered by Andrew Jonathan Longmore on a photographic plate taken on 10 June 1975 at the 1.22m Schmidt telescope at Siding Spring Observatory, New South Wales, Australia. Its brightness was estimated at an apparent magnitude of 17. After further observations Brian G. Marsden was able to calculate the perihelion date at 4 November 1975 and the orbital period as 6.98 years.
The next perihelion date was computed to be 21 October 1981. Tsutomu Seki relocated the comet on 2 January 1981 with a brightness of magnitude 18. It has since been observed in 1988, 1995, 2002 and 2009.
On 17 October 1963, the comet had passed from Jupiter.
During the 2023 perihelion passage the comet brightened to about apparent magnitude 14–15.
Physical characteristics Infrared observations from the Spitzer Space Telescope in 2006 and 2007 revealed that the nucleus of Comet Longmore is roughly in radius, with an absolute magnitude (H) of 7.22 and a density of .
References
External links
at the Minor Planet Center database 77P/Longmore at Gary W. Kronk's Cometography 77P/Longmore at Seiichi Yoshida's website