In the latest of his chronological approaches to understanding science, Asimov spares us the observations of the ancients and begins in 1844 when "A German astronomer, Friedrich Wilhelm Bessel, discovered a star he couldn't see." From this first glimmer of a "dark companion" to Sirius up to the sophisticated contributions of Stephen Hawking, Asimov traces a direct, unclouded course through the heady universe of white dwarfs and red giants, supernovae, pulsars, and the rest. Assuming no prior knowledge, he easily assimilates atomic structure and stellar evolution into the same simple, ongoing explanations. More narrowly focused than Berger's Quasars, Pulsars, and Black Holes in Space (1977), this lacks the cosmic excitement of Branley's Black Holes, White Dwarfs, and Superstars (1976), but by the same token it's less of a trip for the unambitious reader.