Telescopes are wonderful things. They make celestial objects larger and brighter, and turn the few thousand stars we see with our unaided eyes into many millions. But telescopes have one drawback… they give a narrow field of view, often just 1-2º or less, which makes looking at the night sky like looking through a drinking straw. That means you’re usually going to see just one galaxy, nebula, or star cluster at a time. But with so much stuff up there, you do come across some excellent chance alignments of lovely deep-sky objects which fit in a single field of view of a small telescope. Here are four examples of objects which lie in the same low power field of view, plucked from the pages of What To See In a Small Telescope.
To give you a better idea what these objects look like visually in your telescope, I’ve snapped these images through a small 66 mm ED refractor using a Mallincam Extreme.
M81 and M82
You can argue these two fine galaxies aren’t chance alignments because they’re bound together by gravity. M81 is an elegrant “grand-design” spiral, while M82 is more ragged-looking since it endured a recent and violent bout of star formation in and around its core. In small scopes, 8th-magnitude M81 looks like a glowing oval while 9th-magnitude M82 is spindle-like with a small gap near its core. The two are separated by 38′, a little more than half a degree. At a distance of 13 million light years away, the pair is relatively close by as galaxies go.
M97 and M108
Now to a striking contrast in appearance and distance. M97, the Owl Nebula, is a planetary nebula about 2,600 light years away. The slightly fainter galaxy M108, less than a degree to the northwest of M97, lies some 45 million light years away. The Owl is circular while the galaxy is a glowing spindle like M82. Dark sky is needed to see this pair in a small scope; each object shines at 10th magnitude. You can find the pair about 1.5º ESE of the star Merak in the bowl of the Big Dipper.
The Leo Triplet
Now let’s try for three galaxies in one field, each between 8th and 9th magnitude. The galaxies M65, M66, and NGC 3628 under the haunches of the constellation Leo all lie within one degree of each other about 3º SE of the star Chertan. NGC 3628 is the faintest. This nearly edge-on spiral appears larger and has a lower surface brightness than the others. All three are part of the same group of galaxies, and gravity will one day merge them into a single featureless elliptical galaxy.
M53 and NGC5053
If you think all globular clusters look the same, then, well… snap out of it! There are some wonderful variations in brightness, shape, and apparent star density among the dozens of such clusters visible with a small scope. Two contrasting globs lie just a degree east of the star alpha Coma Berenices. The brighter, M53, is easily visible in a small scope, though at magnitude 7.6 it ‘s no retina burner. This cluster lies a distant 60,000 light years away, fairly far for a glob, which is why it is dim. Just 1º ESE of M53 lies the magnitude 9.5 cluster NGC 5053, which looks like a faint reflection of its brighter neighbor. The fainter cluster is about 6,000 light years closer than M53, so its difference in appearance is real… this is a much smaller and less concentrated cluster. It’s a tough object to see in a small scope from urban skies.
To locate these objects, look to your favorite star map or planetarium app (such as Stellarium).
These objects are quite a ways north of the celestial equator, so southern-hemisphere observers will have a hard time with M97/M108 and M81/M82. The Leo Triplet and M53/NGC5053 are visible above the northern horizon in May and June.
For observers in the southern hemisphere, one of the finest “multi-object” targets is surely the “False Comet”, a small aggregation of open star clusters just off the curled tail of Scorpius. It’s just barely visible to northern observers, but in the southern autumn and winter, it’s high overhead. More about the False Comet in this vintage OMA article right here…