Finding faint things with star charts

Dear Fellow Astronomer, I've been hearing from people who've had trouble using star charts to find Comet Lovejoy with binoculars. (By the way, Lovejoy is still in good view.) This gets to the problem of how does anyone learn to find faint things in the sky using charts with binoculars? Or a telescope for that matter?Some figure it out by trial and error, but that's the hard way. A few tricks make for huge shortcuts in mastering this. 1) First: know how big your view is. To compare what you see in binoculars (or the finderscope on the side of a telescope) with what's printed on your chart, you have to know how much sky - how much of the chart - your binoculars are showing you. In other words: what's the binocular's true field of view?For 7-power binoculars, the view is probably about 7° wide. For 10-power binoculars, it's probably about 5° wide. You don't have to know exactly, but you should have a general idea. Now get out your charts. I'll assume you have the Pocket Sky Atlas. because it's super-popular, handy and fairly cheap, and just about ideal for binoculars and small telescopes because it shows stars to as faint as magnitude 7.6 - about the limit of typical binoculars and good finderscopes. Look on the sides of the charts. There's a degree scale running down the sides. This shows declination on the map (like latitude on Earth), but it also shows you how big your 5° field of view appears on the map! On the Pocket Sky Atlas, 5° is 1 inch wide. That's probably a lot smaller than you imagined your binoculars showed. It's much smaller than most constellations. That's why you see so little of a constellation at a time! Remember this size. Maybe draw it on the inside of the front cover so you'll always have it handy. The star patterns on the charts that fit into that size circle are the star patterns you'll see in your field of view. 2) Which way is up? On star charts, celestial north is up. On the sky, celestial north is always the direction toward Polaris, the North Star. No matter at what angle that is from wherever you're looking. You do need to know how to spot Polaris. Once you do, you'll know which way is celestial north from wherever you're looking. Turn your chart around so its top matches that direction. 3) Start from a naked-eye landmark near the object you're hunting for. You need to know at least a few constellations. (There's an excellent naked-eye constellation map in the center of each month's Sky & Telescope The constellations provide starting points for zeroing in on the exact point where a faint thing on your chart should be. On the chart, working from a starting point you know to your faint target, look for star patterns - triangles, kite shapes, whatever - marking the path. In choosing these patterns, use the brightest available stars that will fit in your field of view. Now, with the binoculars (or your telescope's finder), work your way along this trail, matching the chart with what you see, step by step. This is called "star-hopping." If you get lost, start over. You'll get the hang of it. And then you'll know how to do it for the rest of your life. You'll discover that when you know the exact point in your field of view to examine, it's amazing how much deeper you can see. And how much more confident you'll be that you've indeed found what you were looking for. I hope you'll use these tips to help you enjoy the Comet Lovejoy, while you still can! Alan MacRobert Senior Editor, Sky & Telescope P.S. One reason binoculars are nice is they show a view that's right-side up and also is not mirror-imaged. Some telescopes and finderscopes show views that are upside-down or tilted, and/or are mirror-imaged.