Messier 92 is one of the oldest and brightest globular clusters in the Milky Way, containing roughly 330,000 stars packed into a dense, spherical formation. Discovered by Johann Elert Bode in 1777, it is slightly less prominent than its neighbor M13 but remains a favorite among astrophotographers for its clarity and structure. The cluster is easily captured with a wide range of telescopes and cameras, making it accessible for both beginners and advanced imagers. Its relatively low metallicity and ancient age provide a glimpse into the early history of our galaxy.
Names and Catalog numbers
- Messier 92
- M92
- NGC 6341
- Melotte 168
Position and the cosmic neighborhood
Messier 92 is situated in the northern part of the constellation Hercules, north of the Keystone asterism and between the stars Eta Herculis and Iota Herculis. It forms a triangle with the two northernmost stars of the Keystone, making it straightforward to locate for observers and astrophotographers. The cluster is positioned just under Hercules’ arm, in a region that is rich with deep-sky objects, and lies not far from the more famous Messier 13. Several faint background galaxies can be captured in wide-field images of the area, adding interest to astrophotographic compositions.
Nice to Know
- Messier 92 is estimated to be about 14 billion years old, making it nearly as old as the universe itself.
- It is visible to the naked eye under dark skies and is an excellent target for both visual observers and astrophotographers.
- The cluster is very metal-poor, composed mainly of hydrogen and helium, which is typical for ancient globular clusters.
- Astrophotographers appreciate M92 for its brightness, compactness, and the presence of faint background galaxies in wide-field images.
Brightnes, distance and size
Messier 92 shines at an apparent magnitude of about 6.3, making it visible without optical aid in very dark skies and easily observed with binoculars or small telescopes. Its distance from Earth is approximately 26,700 to 27,000 light-years, and it spans about 109 to 110 light-years in diameter. The cluster covers roughly 14 arcminutes in the sky, appearing a little less than half the width of the full Moon, which makes it a striking and rewarding target for astrophotography.
