Limits on the nucleus of Halley's Comet

Abstract

We report here a limiting magnitude to the brightness of the nucleus of Halley's Comet which, together with published interpretations of the comet's visual light curve in 1910 and estimates of the magnitude of non-gravitational forces that have modified the comet's orbital motion throughout the past five apparitions, places some interesting limits on the physical properties of the nucleus. We find that the nucleus is probably ∼4km across, has a surface albedo of 0.17, and a mass of 3.4 × 1016 g. Comet Halley may not be recovered until early November 1984, but could be found as early as late September–early October 1982.