Visual Surveys of Extended Objects
Andrew Norton · 2026
This chapter describes two visual surveys of extended objects made before the use of photographic recording. It begins with a description of the 1784 catalogue by Charles Messier that includes objects ranging from stellar remnants to star clusters to external galaxies. The chapter then describes the various catalogues compiled by William Herschel, Caroline Herschel, and John Herschel, which culminated in the New General Catalogue of Nebulae and Clusters of Stars compiled by John Louis Emil Dreyer in 1888, along with its two later Index Catalogues. The chapter includes explanatory boxes about the Milky Way Galaxy, the Local Group of Galaxies, star clusters, planetary nebulae and supernova remnants, and galaxies in general.