M44: A Beehive of Stars

M44 is a prominent open cluster of stars. Nicknamed Praesepe and “The Beehive”, it is one of the few open clusters visible to the unaided eye. M44 was thought to be a nebula until Galileo used an early telescope to resolve the cluster's bright blue stars. These stars are visible in the above image . M44 , which is thought to have formed about 400 million years ago, is larger and older than most other open clusters . The Beehive Cluster lies about 580 light-years away, and spans about 10 light-years across. When viewed with a powerful telescope, hundreds of stars become visible.