185P/Petriew

Lore & Background

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 searching for the Crab Nebula. He estimated the comet had an apparent magnitude of 11, a coma about three arcminutes across, and no tail. For this discovery, Petriew was awarded the Edgar Wilson Award in 2002. Alan Hale imaged the comet with a CCD on 19 August and estimated its magnitude at about 13.

The comet brightened during August, reaching magnitude 10, with a coma diameter reported as 2 to 4 arcminutes. No tail was observed visually, but CCD imaging revealed a narrow tail. Spectographic observations in September 2001 found normal production rates of diatomic carbon and water for a Halley-type comet. The comet was quickly found to be periodic with a period of about 5.5 years. It had approached Jupiter to 0.146 AU on 3 July 1982, decreasing its perihelion distance from 1.37 AU to 1.00 AU.

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, at magnitude 16.1 with a diffuse coma 0.2 arcminutes across. After recovery, it was given the number 185P.

Reader's Guide

185P/Petriew holds significance as the third comet discovered by a Canadian amateur astronomer, highlighting the contributions of amateur observers to cometary astronomy. Its discovery during a star party underscores the role of public astronomy events in scientific discovery. The comet's orbital history, including a close approach to Jupiter in 1982 that reduced its perihelion distance, illustrates how gravitational interactions can alter cometary orbits. The recovery in 2007 by a team using a modest 0.25m telescope demonstrates the ongoing accessibility of comet observation to amateurs. Additionally, 185P/Petriew is potentially the parent body of a meteor shower first observed on 26–27 October 2024 with a radiant in Lyra, linking it to broader meteor science. Its legacy includes the Edgar Wilson Award for its discoverer and its designation as a numbered periodic comet.

Did You Know?

• Discovered visually by amateur astronomer Vance Avery Petriew during a star party while searching for the Crab Nebula.
• Petriew became the third Canadian amateur astronomer to discover a comet.
• The comet's perihelion distance was decreased from 1.37 AU to 1.00 AU after a close approach to Jupiter on 3 July 1982.