M44 - Praesepe
K1 M44: A Beehive of Stars
Credit & Copyright: Wil Milan
Explanation: M44 is a prominent open cluster of stars. Nicknamed
Praesepe and "The Beehive", it is one of the few
open clusters. 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.
K2 Praesepe: A Pair of Colliding Star Clusters?
One of the prettiest sights in the night sky may be hiding a destructive secret. The Beehive (M44), also known as Praesepe, is an open cluster of several hundred stars located 570 light-years away in the constellation Cancer. However, according to a team led by Karen Holland and Richard Jameson (University of Leicester), the 800-million-year-old Beehive actually consists of two colliding star clusters.
By analyzing the X-ray brightness of the Beehive's individual members, the researchers identified a concentration of older stars (which have weaker emissions). Yet stellar mingling should have evened out any such segregations long ago. In addition, a close examination of gravitational interactions within the cluster revealed that it is unstable. The stars are moving so quickly that the Beehive will disintegrate within only 10 million years.
According to Jameson and
Holland, the obvious explanation for these peculiar properties is that the
Beehive contains two open star clusters in the process of colliding.
Details will appear later this year in the Monthly Notices of the
Royal Astronomical Society.
K3 Messier 44 by SDSS