David Levy is probably most famous as the co-finder of the comet Shoemaker-Levy 9, which slammed into Jupiter in 1994. The discovery, with his friends Gene and Carolyn Shoemaker, was the culmination for Levy of decades of comet-hunting.
Deep Sky Objects is not about Levy's beloved comets, but about other interesting objects in the deep sky - that is, outside our Solar System. Comet-hunters scan the sky constantly, hoping to find a fuzzy, moving object. In the process, they see many interesting astronomical phenomena. Deep Sky Objects is an annotated list of Levy's favourite non-comet phenomena: open star clusters, dark and light nebulae, variable stars and others. But it is more than just a list. Levy intends to guide beginners into the field of deep sky objects, and to offer a taste of the night sky to observers.
The concept of Levy's list is loosely based on a catalogue made by Charles Messier, an 18th-century French astronomer, of objects that he found while searching for comets. Levy has looked for each of Messier's objects, and found others of his own. For each of Levy's objects, he supplies official cataloguing information, position, magnitude, distance etc, plus a paragraph about Levy's observations, and (usually) a photograph taken by Levy or one of his associates.
Where appropriate, he provides brief, easy explanations of phenomena, such as the formation of new stars, and how we discovered our galaxy is spiral.
Levy adds anecdotes about other astronomers, modern and historical, about his own career, including his earliest sky observations, and his family life, which seems centred on comethunting.
There are appendices of technical information about his objects, including star charts.
Levy wants to encourage beginners, and is careful that his list should include objects that can be found even by someone in a light-polluted city. Unfortunately for Australian readers, Deep Sky Objects, like most works of astronomy, is based on the northern hemisphere sky - many of the objects will not be visible in Australia. However, Levy does include some objects visible only from the southern hemisphere. He notes The Jewel Box, a star cluster in Crux (the Southern Cross), as "this beautiful cluster is part of the reason that observers travel to the southern hemisphere".
Throughout this enthusiastic book Levy is unfailingly generous to colleagues and friends, especially his wife Wendee, and eager that others should share his love of comets and other astronomical objects.
Deep Sky Objects is an excellent introduction to visual astronomy.
