Watching out for Halley's comet

Abstract

Halley's comet returns to the vicinity of the sun about every 76 years. Between August 1985 and the end of 1986 it is confidently expected that the comet will be brighter than 14th magnitude and thus, under ideal observing conditions, detectable with a telescope smaller than 15 cm objective diameter. The author reviews how one should go about observing Halley's comet using small telescopes, binoculars and the naked eye. Unfortunately, northern hemisphere observers will not be seeing a brilliant comet with a tail stretching from horizon to the zenith. For them, Halley's comet will appear as a silvery grey hazy object, like a small spherical mass of vapour. Southern hemisphere observers will be more fortunate and will, during March and April 1986, see both the head of the comet and a tail stretching about 30 degrees across the sky.