Messier 67 is one of the oldest known open clusters, estimated to be around 3.7 to 5 billion years old. It contains over 500 stars, including about 200 white dwarfs and 11 bright orange K-type giant stars. The cluster is well-populated with negligible amounts of dust obscuration, making it an excellent target for astrophotographers. M67’s age and composition make it a valuable object for studying stellar evolution, as it contains stars at various stages of their life cycles.
Names and Catalog numbers
- King Cobra Cluster
- Messier: M67
- NGC: NGC 2682
- Melotte: Mel 94
Position and the cosmic neighborhood
Messier 67 can be found in the constellation Cancer, about 1.7 degrees west of the star Acubens (Alpha Cancri). It lies roughly 8 degrees southeast of Delta Cancri, one of the stars in the Y-shaped asterism known as “The Beehive.” The cluster’s location, far from the galactic plane, contributes to its longevity and makes it an interesting object for study.
Nice to Know
- M67 is one of the oldest known open clusters, with an age similar to our Sun.
- The cluster contains about 30 blue stragglers, which are stars that appear younger and hotter than expected.
- M67 has undergone mass segregation, with heavier stars concentrated towards the center.
- The cluster is expected to exist for another 5 billion years.
Brightness, distance and size
Messier 67 has an apparent magnitude of 6.1, making it just barely visible to the naked eye under optimal conditions. It is located approximately 2,700 light-years from Earth and spans about 12 to 21 light-years in diameter. In the night sky, M67 appears to cover an area of about 30 arcminutes, roughly equivalent to the size of the full Moon. This combination of brightness and size makes M67 an excellent target for both binoculars and small telescopes, with larger instruments revealing more of its stellar population.
