Here is a list of 10 great deep sky objects you can observe in May in a 100-200mm (4-6″) telescope.
One of the best deep sky objects in the northern sky is the beautiful galaxy, M51 found in Canes Venatici. It can be found just 3.5° southwest of Alkaid, the last star in the handle of the Big Dipper.
1. NGC 4565 (The Needle Galaxy)
Let’s start with the one that should never be left off a May list. This edge-on galaxy in Coma Berenices is stunning in a 150–200mm scope. Under dark skies, you’ll see a razor-thin streak with a bright central bulge—and if conditions cooperate, a hint of the dark dust lane cutting through it.
2. Messier 13 (Hercules Globular Cluster)
Yes, it’s a Messier—but it earns its place. In a 6–8″ scope, M13 explodes into hundreds of resolved stars, especially with a bit of magnification. It’s a benchmark object for a reason.
3. NGC 4449
An irregular galaxy in Canes Venatici that’s often overlooked. It appears as a soft, elongated glow, but in larger apertures you may notice patchiness. It’s a nice contrast to the more symmetrical spirals nearby.
4. Messier 94
Compact, bright, and forgiving of light pollution. M94’s intensely bright core makes it stand out even when conditions aren’t perfect—a great object to show beginners.
5. NGC 4631 (The Whale Galaxy)
This elongated galaxy in Canes Venatici really shines in a 200mm telescope. Look for its slightly warped shape and uneven brightness—some observers report hints of mottling along its length.
6. NGC 4656 & NGC 4657 (The Hockey Stick)
A fun and unusual interacting galaxy pair near the Whale Galaxy. In a 6–8″ scope, you can detect the bent, distorted shape that gives it its nickname. It’s subtle, but rewarding.
7. Messier 3
Still one of the best globular clusters in the sky. In a mid-sized scope, it shows a rich, grainy texture with stars resolving across the face.
8. NGC 6210 (The Turtle Nebula)
A small but bright planetary nebula in Hercules. It looks like a slightly bluish star at low power, but crank up the magnification and it becomes a tiny disk. Great test of seeing conditions.
9. NGC 4244 (The Silver Needle Galaxy)
Another edge-on galaxy, but much fainter and more delicate than NGC 4565. It’s long, thin, and ghostly—best observed under dark skies with patience.
10. Messier 5
A superb globular cluster in Serpens. Slightly more compact than M13, but incredibly rich. In a 150–200mm scope, it resolves beautifully with a bright, condensed core.
