…continuedFuzzies in Your Future:
An Introduction to Deep-Sky Objects
Beyond the Milky Way
Now for the really exotic stuff. Beyond the Milky Way are the galaxies. Spot a galaxy and you're peering millions of light-years into the universe at large. Obviously, these incredibly remote targets present a challenge for beginners. Although galaxies come in various classifications, you might consider the distinctions academic because most galaxies appear featureless in small telescopes. But there are exceptions.
The Andromeda Galaxy is one. Even though it's 2.5 million light-years away, the Andromeda Galaxy, or Messier 31 (M31), is visible to the unaided eye as a tiny, diffuse cloud on a perfect autumn night. A spiral system like our Milky Way, M31 is inclined somewhat to our line of sight. Under pristine skies, good binoculars will show M31 as an elongated wisp with a bright central condensation (this bright, oval bulge is the only part that readily punches through suburban skyglow). A short-focus, wide-field telescope can frame the whole galaxy in a low-power eyepiece. Bumping up the magnification (again, under very dark skies) might provide hints of spiral arms and of pencil-thin dark lanes the silhouettes of dust clouds congregating in M31's midplane.
Two galaxies in the Northern Hemisphere's springtime sky offer different perspectives. The Whirlpool Galaxy, Messier 51 (M51) in Canes Venatici, is presented fully face-on. Despite being 35 million light-years away, M51's spiral structure is distinct through telescopes as small as 8 inches under dark skies. By contrast, a spiral in Coma Berenices called NGC 4565 appears almost exactly edge-on. About 10 million light-years closer than the Whirlpool, this galaxy's spindly form stretches across a high-power field of view if sky conditions are good.
And a mere 9 million light-years away is NGC 253, a prominent galaxy in the Southern Hemisphere springtime constellation of Sculptor. Aligned not quite edge-on to our view, cigar-shaped NGC 253 displays an uneven, grainy texture in good 4-inch telescopes, and it is a relatively easy catch in binoculars.
M51 stands apart in another way: it's really two galaxies, not one. A smaller body, NGC 5195, orbits the main spiral (you can see it in the photo above, near the tip of one spiral arm). And while M51's spiral structure can be seen at the eyepiece only under relatively dark skies, the system's double nature can be perceived as two tiny, unequal dim blurs even with a small telescope contending with suburban viewing conditions.
Yes, it's true I see fuzzies in your future. If you're like the other backyard astronomers I know, you'll be drawn to the deep sky not in spite of its challenging nature, but because of it. You'll find yourself targeting the same objects over and over. Just as you strain to glimpse fine detail on Mars or Jupiter, you'll develop a thirst for your best-ever observation of a particular star cluster, nebula, or galaxy, and soon you'll develop your own list of personal favorite friends to visit again and again through the seasons.
For the fine points of deep-sky observing, plus more about the objects you can see in small telescopes, browse through the How To and Observing sections of this Web site. You'll be hooked in no time.
Oh-oh, now I see trouble. My crystal ball shows you lusting after larger telescopes and better star charts. But don't blame me; I'm just the messenger. Five dollars, please.