119P/Parker–Hartley is a Jupiter-family comet with a 7.44-year orbit around the Sun. It is co-discovered by two astronomers, Quentin A. Parker and Malcolm Hartley.
Observational history Robert H. McNaught reported the discovery of a comet on a photographic plate taken by Quentin A. Parker and Malcolm Hartley using the Siding Spring Observatory's 1.2-m UK Schmidt Telescope on 2 March 1989. At the time of discovery, the comet was a diffuse 16th-magnitude object within the constellation Aries. Additional observations, including a precovery image from 11 February 1989 that showed a diffuse trail, allowed astronomers to determine that Parker–Hartley is a periodic comet that has reached perihelion nearly two years prior.
Further investigation revealed that the comet was actually discovered as early as 1986, when it was initially identified as an asteroid called 1986 TF, where it was first spotted by Poul B. Jensen and Antonin Mrkos from August to October 1986. Jensen reported that on his reanalysis of the 1986 plates he took from the Brorfelde Observatory, it was a slightly diffuse object relative to other minor planets, albeit without central condensation. While initially contradicted by the observations made by Antonin Mrkos at the Klet' Observatory where there's no reported activity, reanalysis of the observatory's 1986 photographic plates in 2000 later revealed that the comet did show some weak activity at the time.
The comet was recovered on every subsequent apparition since; on 1996, 2005, 2014 and 2022, respectively. It is expected to return by 2030.
Physical characteristics Observations from the Hubble Space Telescope in 2005 revealed that the nucleus of Comet Parker–Hartley is about in diameter.
Orbit , Comet Parker–Hartley is in a heliocentric orbit that takes about 7.437 years to complete, with a perihelion distance about from the Sun, inclined about 7.4 degrees to the ecliptic. Its orbit also allowed Shuichi Nakano to classify the comet as a quasi-Hilda object.
This comet makes several close approaches to Jupiter between 1984 and 2161. Prior to its discovery, Parker–Hartley flew past Jupiter at a distance of in May 1984. Around 16 March 2161, the comet will pass about from the giant planet.
Notes
References
External links
at the Minor Planet Center database 119P/Parker–Hartley at Gary W. Kronk's Cometography