C/1995 O1 ( Hale-Bopp 彗星)

＊　G A R Y W. K R O N K ' S C O M E T O G R A P H Y　＊ After several months of no comet discoveries, which marked one of the longest dry spells in recent years, Alan Hale (Cloudcroft, New Mexico, USA) and Thomas Bopp (near Stanfield, Arizona, USA) independently discovered a new comet on 1995 July 23. The comet was found in Sagittarius, not far from the globular cluster M70. It was described as diffuse, with some condensation, and about magnitude 10.5. Both Hale and Bopp had been observing M70 when they noticed the diffuse glow just a short distance away. The discovery was incredible considering the comet was then 7.1 AU from the sun. Prediscovery images were later discovered. T. Dickinson (Chiricahua Mountains, Arizona, USA) found the comet on an image exposed on 1995 May 29. Incredibly, R. H. McNaught (Anglo-Australian Observatory, Australia) found a prediscovery image on a plate exposed over two years earlier, on 1993 April 27. The comet's total magnitude was then 18 and the coma was 0.4 arc minute across. The orbit indicated the comet was then 13.0 AU from the sun!

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