For more than two centuries, amateur astronomers have earned their stripes by observing the 109 star clusters, nebulae, and galaxies cataloged by French comet hunter Charles Messier. Sir Patrick Moore has compiled a new list of 109 deep-sky delights, the Caldwell Catalog, which covers the entire celestial sphere. Stephen James O'Meara has observed all 109 Caldwell objects and Deep Sky Companions presents his beautiful sketches and detailed visual descriptions and discusses each object's rich history and astrophysical significance. The latest fundamental data on each object are tabulated, and the book's star charts will lead observers to each object's precise location. Stephen James O'Meara is known worldwide for his precise drawings of astronomical objects as seen through the telescope. Among his many astronomical achievements, he was the first to sight Halley's Comet on its 1985 return; he noticed the dark spokes in Saturn's B ring before the Voyager 1 spacecraft imaged them; and he was the first person to determine the rotation period of the distant planet Uranus. The International Astronomical Union named asteroid 3637 O'Meara in his honor. He is also the author of Deep Sky Companions: The Messier Objects (Cambridge, 1998) and co-author with his wife, Donna Donovan O'Meara, of Volcanoes: Passion and Fury (Sky Publishing, 1994).