29P/Schwassmann-Wachmann, an “Outbursting” Comet to Watch

Abstract

This unusual comet deserves special mention. True, it will not become a bright telescopic object anytime between 2017 and 2027 (unless something very unusual happens!), but because it moves in an almost circular orbit between the giant outer planets Jupiter and Saturn it is, like these planets, accessible every year throughout its orbit. Most of the time, it will appear as nothing more than a speck of light between magnitudes 17 and 18, out of the range of visual observers unless they are fortunate to have access to telescopes of 1 m diameter or thereabouts. Nevertheless, in view of its past behavior, there will no doubt be many occasions when it will be an easy object for telescopes having apertures of just one quarter of that diameter, and it is this that makes comet 29P such a fascinating object for visual observers (Fig. 14.1).