Every amateur astronomer has at least heard of the many different catalogs of the deep-sky objects. These catalogs are, in general, readily available. Charles Messier's famous catalog is perhaps the most widely known, along with Sir Patrick Moore's later addition to it, the Caldwell Catalogue. Then there is the Herschel Catalogue...and many others.

However, very few amateur astronomers are in a position to choose the best catalog for their particular deep-sky observing program, and fewer still realize how to use them and even how many there are out there

The Amateur...