The Herschel 400 is a list of 400 galaxies, nebulae, and star clusters, picked from over 2,500 deep-sky objects discovered and catalogued by the great eighteenth-century astronomer Sir William Herschel and his sister Caroline. It comprises 231 galaxies, 107 open clusters, 33 globular clusters, 20 planetary nebulae, 2 halves of a single planetary nebula, and 7 bright nebulae. In this guide Steve O'Meara takes the observer through the list, season by season, month by month, night by night, object by object. He works through the objects in a carefully planned and methodical way, taking in some of the most dramatic non-Messier galaxies, nebulae, and star clusters in the night sky. Ideal for astronomers who have tackled the Messier objects, this richly illustrated guide will help the amateur astronomer hone their observing skills.