26P/ Grigg-Skjellerup Comet

Astronomical specifications:

Discovery:

• John Grigg (Thames, New Zealand) was engaged in his monthly sky survey when he discovered this comet in Virgo on 1902 July 23.27. Grigg was using a 3.5-inch refractor (power=25x) and said the comet looked like an extremely faint nebula, and was "about twice the diameter of Jupiter." Grigg was able to catch a glimpse of the comet under mostly cloudy skies on the 24th, but his solid confirmation did not come until the skies cleared on the 27th. After that observation he could finally send out notices. Again battling the weather, Grigg was able to again observe the comet on July 30 and August 2 and 3, the latter of which was his final observation. Grigg's notices failed to reach the authorities in time, so that he remained the only observer. Shortly after his final observation he computed a parabolic orbit. Up to that time he thought he might have caught the return of some other periodic comet, but his orbit revealed this was a hitherto unknown comet.
• James Francis Skjellerup (Cape Town, South Africa) discovered a comet on 1922 May 17. The general concensus during the earliest observations was that the comet's total magnitude was around 11, while the coma diameter was between 4 and 5 arc minutes. By the end of the month astronomers had already found that the observations were indicating the comet was moving in a short-period orbit. Shortly after mid-June, R. T. Crawford and W. F. Meyer (Berkeley Astronomical Department, California, USA) pointed out the similarities between the orbits of Grigg's comet of 1902 and that found by Skjellerup. Because of the rough nature of Grigg's observations, Crawford and Meyer added that identity could not be completely confirmed until the comet returned in 1927. Identity was fully confirmed in that year.

Historical Highlights:

External links:

• Cometography.com: Comet 26P/Grigg-Skjellerup description.

Grigg-Skjellerup missions: