Where I live, 30 miles west of downtown Philadelphia (near historic Valley Forge, Pennsylvania), the glow of the nighttime sky is often bright enough that I can read my star charts without the aid of a red flashlight. Sadly, for most of the stargazing community in our country, this is a pretty typical situation. Yet despite such blatant intrusions on the once sacred darkness of the night sky, many deep sky wonders can still be seen and enjoyed in a small telescope. In fact, some keen-eyed observers have even been able to glimpse the brightest quasar, 13th-magnitude 3C 273 in Virgo. Considering that the deep sky object is at a distance of around 2 billion light-years, it is amazing that it can be seen at all under such conditions, let alone with apertures as small as 5 or 6 inches!
Presented here is a table of 111 deep sky showpieces scattered around the heavens, most of them visible from midnorthern latitudes through even the brightest of skies. Since stars have the highest per-unit-area brightness, double and multiple stars and bright star clusters dominate the selection. Nebulae and galaxies are still well represented even though these faint fuzzies suffer the most from light pollution. You can readily find all of them within their respective constellations using a good star atlas such as Sky Atlas 2000.0, and the vast majority are plotted in more basic atlases and on detailed star maps. In fact, many of these hidden treasures appear on Sky & Telescope's monthly centerfold star map.
Deep Sky Observing Tips
A few observing hints are in order. While low magnifications and wide fields of view are typically used for finding deep sky objects, higher magnification has the benefit of darkening the background sky — something to keep in mind when you're looking through light pollution. Close doubles and tight clusters (especially globulars) are best seen on nights of steady seeing, while nebulae and galaxies should be saved for nights when transparency is excellent. All deep-sky objects are at their best when on or near the meridian and, therefore, highest in the sky.
Use direct vision where color perception and resolution are important, and averted vision (looking slightly to one side of the object) for seeing faint details. In the latter case, a dark opaque cloth covering your head down to your shoulders will help prevent unwanted light from streetlights, passing cars, and the glowing sky itself from ruining your dark adaptation. And finally, as a rule, the later at night you observe, the less light pollution you will have to contend with as businesses close, neighbors go to bed, and the busy world around you shuts down for the night.
Deep Sky Wonders and Deep Sky Objects to Observe
The table appears on the next three pages (click below on Next Page). For more information, we have made the original version of this article, which appeared in the April 2003 Sky & Telescope., available. Download Mullaney's 111 Deep-Sky Wonders for Light-Polluted Skies as a 900-kilobyte PDF file.
While it's true that light pollution in its various forms has sapped much of the quality out of modern living, the showpieces tabulated above at least illustrate that observers don't need to let bright skies rob them of the joys of stargazing. No matter where you live, the stars and deep sky objects are still there for you to enjoy.