M 67 (also designated as NGC 2682)
is an open star cluster that lies approximately 2700 light years
in the constellation of Cancer, the crab. It was discovered by Johann
Koehler in 1779 and Charles Messier added it to his catalog in 1780.
M 67 is the oldest (3-5 billion years old) star cluster in the Messier
catalog. Most open clusters disperse over time. It contains over
100 sun-like stars and numerous red giants.