This comprehensive coverage of the thousands of celestial objects outside our solar system. The objects are grouped according to constellation, and their definitions feature names, coordinates, classification, and physical description, along with hundreds of visual aids. Volume I of the three-volume work covers Andromeda to Cetus.
Here's a sample of other books in this Dover category
An Introduction to Celestial Mechanics by Forest Ray Moulton Classic text still unsurpassed in presentation of fundamental principles. Covers rectilinear motion, central forces, problems of two and three bodies, much more. Includes over 200 problems, some with answers.
Amateur Astronomer’s Handbook by J. B. Sidgwick Timeless, comprehensive coverage of telescopes, mirrors, lenses, mountings, telescope drives, micrometers, spectroscopes, more. "Highly recommended for very serious nonprofessional astronomers." — A Guide to the Literature of Astronomy. 189 illustrations.
Kepler by Max Caspar Definitive biography covers Kepler's scientific accomplishments — laws of planetary motion, work with calculus, optics, more — plus public and personal life, more. Introduction and Notes by Owen Gingerich.