Double-star observing offers many attractions for amateur astronomers — light pollution, whether from man or Moon, has little impact on the image, and even a modest 3-inch telescope will show all the best doubles in the sky. In my opinion, a pretty double in a small scope is lovelier than a faint smudge of a galaxy in a giant light bucket.

Many amateurs enjoy the challenge of splitting very difficult (close) doubles. Occasionally I do too. But mostly I enjoy doubles simply for their beauty. After observing doubles for several years I have developed some criteria for choosing the most visually pleasing pairs or multiples, and contrasting color tops the list. The more contrast, the better. The well-known summer jewel Albireo (β Cygni), the gold and green pair Almach (γ Andromedae), and the orange and blue suns of 24 Comae Berenices are the color-contrast leaders.

Lacking distinctive hues, the prettiest pairs are those reasonably well matched in brightness. Castor (α Geminorum) is a particularly fine example of this. Stars with widely differing magnitudes just don't have the same visual appeal as a pair of twin suns blazing away in the eyepiece.

I also prefer double-star systems in which one of the stars is magnitude 6 or brighter. Dim doubles simply aren't as captivating and they're also harder to find.