| 185P/Petriew | |
| Discoverer: | Vance Avery Petriew |
| Discovery Date: | 18 August 2001 |
| Designations: | P/2001 Q2, P/2007 A3 |
| Orbit Ref: | [1] |
| Epoch: | 17 April 2015 |
| Aphelion: | 5.267 AU |
| Perihelion: | 0.934 AU |
| Semimajor: | 3.100 AU |
| Eccentricity: | 0.6988 |
| Period: | 5.46 years |
| Inclination: | 13.997° |
| Asc Node: | 214.101° |
| Arg Peri: | 181.938° |
| Tjup: | 2.750 |
| Earth Moid: | 0.061 AU |
| M1: | 13.6 |
| Last P: | 12 July 2023 |
| Next P: | 26 December 2028[2] |
185P/Petriew is a periodic comet with an orbital period of 5.5 years. It was discovered by amateur astronomer Vance Avery Petriew on 18 August 2001.[3]
Vance Avery Petriew discovered the comet visually with a 0.51-m reflector telescope during a star party in Cypress Hills, Canada, on 18 August 2001, while he was searching for the Crab Nebula.[3] He became the third amateur Canadian to discover a comet.[4] Petriew estimated that the comet had an apparent magnitude of 11, a coma about three arcminutes across and no tail.[5] For the discovery V. A. Petriew was awarded the Edgar Wilson Award in 2002.[6] The comet was also observed by other participants of the party. Alan Hale imaged the comet with a CCD on 19 August and estimated the comet had an apparent magnitude of about 13.[5]
The comet continued to brighten during August, reaching magnitude 10. The coma diameter was reported to be 2 to 4 arcminutes. No tail was observed visually, but CCD imaging revealed the presence of a narrow tail.[3] The comet was observed spectographically in September 2001 and was found to have normal production rates of diatomic carbon and water for a Halley-type comet.[7] The comet was quickly found to be periodic, with a period of about 5.5 years. The comet had approached Jupiter to a distance of 0.146AU on 3 July 1982[1] and as a result its perihelion distance was decreased from 1.37 AU to 1.00 AU.[3]
The comet was recovered on 11 January 2007 by F. Fratev, E. Mihaylova, and A. Kirchev using a 0.25m reflector telescope at Zvezdno Obshtestvo Observatory in Plana, Bulgaria. The comet then had an apparent magnitude of 16.1 and a diffuse coma 0.2 arcminutes across.[8] After recovery, the comet was given the number 185P.[9]
185P/Petriew could be the parent body of a meteor shower that was first observed on 26–27 October 2024 with a radiant in Lyra.[10]