Messier 34, also cataloged as NGC 1039, is a bright and loosely scattered open star cluster in Perseus that makes an excellent target for wide-field astrophotography. Spanning roughly 0.8° (48′) across the sky, it fills a generous portion of the frame and pairs beautifully with short focal-length refractors and telephoto lenses. Its scattering of moderately bright blue-white stars stands out cleanly against the dark background, making it forgiving for shorter total exposure times. Because the cluster is bright and sparse rather than densely packed, it rewards careful star-color calibration and gentle stretching that preserves the delicate distribution of its members.
Names and Catalog numbers
- M 34 (Messier 34)
- NGC 1039
- Mel 17 (Melotte 17)
Position and the cosmic neighborhood
Messier 34 sits in the northern constellation Perseus at a right ascension of 02h 42m and a declination of +42° 43′, placing it high in the autumn and early winter skies for northern observers. This region of the Milky Way is rich with well-known deep-sky targets, and the cluster is conveniently framed roughly midway between the bright stars of Perseus and the neighboring constellation Andromeda. Its high northern declination keeps it comfortably above the horizon for long stretches of the night from mid-northern latitudes, giving imagers ample time to accumulate frames. With a physical diameter of about 23 light-years, the cluster forms a compact stellar family that is easy to locate under moderately dark skies.
Nice to Know
- With an angular size of 0.8° (48′), Messier 34 is large enough to be resolved by binoculars and is ideally suited to wide-field imaging setups.
- The cluster lies about 1,660 light-years from Earth, making it one of the nearer bright open clusters accessible to amateur astrophotographers.
- Its true physical extent of roughly 23 light-years contains a loose, sparse arrangement of stars that photographs cleanly against the dark sky.
- Messier 34 carries several designations, including Mel 17 and NGC 1039, and it approaches us with a radial velocity of -9.8 km/s.
Brightness, distance and size
It lies about 1,660 light-years from Earth and spans roughly 23 light-years across. On the sky it appears about 0.8° (48′) in size.
