Deep-Sky Objects

A different kind of reward comes from seeking out the vanishingly faint glows of star clusters and galaxies thousands or millions of light-years away. Merely finding these eerie phosphorescences amid vast expanses of stars is most of the fun. To do this you will need to become handy with sky charts and adept at finding your way through star fields. This is much easier with binoculars than a telescope, so the binoculars are excellent training.

If you have already learned some of the constellations with the naked eye, you'll discover that binoculars show countless new stars in what used to be blank spaces. Sweep from one bright star to another in familiar constellations to get used to finding your way around.

Pay close attention to the size of your field of view; keep in mind how much sky it covers as shown on the map you're using. Locate two bright stars that just fit into the edges of your binoculars' field, and see how many degrees apart they are on your map. You can make a wire ring with this diameter and place it on the map. It will instantly show the binoculars' field of view you can expect. By sliding the ring around on the map, you'll see how much territory you have to cross to get from one place to another.

If your sky is dark and free of light pollution, a pair of 7x50 or 10x50 binoculars should show all stars 9th magnitude and brighter and most deep-sky objects that are described as 8th magnitude or brighter. Objects near this limit will be quite difficult — but that's the challenge! Under typical suburban light pollution, take 1 magnitude off these limits. That still leaves a lot to see.

As with a telescope, making good use of your charts and reference books is crucial to success.