Lost comet 72P Denning – Fujikawa recovered
2014 July 21
This periodic comet was discovered by William F. Denning of Bristol, the BAA’s first Comet Section Director, on 1881 Oct 4.13 but was then lost until its accidental recovery by Shigehisa Fujikawa (Onohara, Kagawa, Japan) on 1978 Oct 9.81. The comet has an orbital period of around 9 years but was missed at the next three returns despite careful searches.
The comet was recovered in the constellation of Cetus on 2014 June 17.8 by Hidetaka Sato (Japan), who is an obstetrician by profession and an amateur astronomer based at the Gunma Astronomical Observatory, Tokyo, although the observations were made remotely using the iTelescope 0.43, f/6.8 astrograph at Siding Spring, Australia. The comet was found to be moderately condensed with a coma 25″ in diameter at magnitude 16.8.
Sato found the comet more than a degree away from its predicted position and made confirmatory observations with the same telescope on 2014 June 18.8. His subsequent positions allowed S. Nakano to link 43 observations spanning 1881-2014 to produce an accurate set of orbital elements which will, hopefully, ensure that the comet will be recovered regularly at future returns. The elements show the comet reached perihelion on 2014 July 11.63 at a distance of 0.78 au from the Sun. For the current return the closest approach to Earth was 1.23 au and in early August the comet will be a dim mag 17 object situated in Gemini. Large telescopes and CCD imaging will be needed to record it.
A concise history of this comet written by Gary Kronk can be found at http://cometography.com/pcomets/072p.html