M11, a rich and compact open cluster of
2900 middle aged stars located in the summer constellation of
scutum. It is also known as the Wild Duck Cluster since to observers
it resembles a triangular pack of flying geese. The stellar members
are approximately 220 million years old and roughly 600 of its
stars are greater than 15th magnitude making it one of the brightest
and most compact open clusters. It lies 6000 light years away
and spans some 21 light years in diameter. Discovered in 1681
by Gottfried Kirch, M11 became part of Charles Messier's famous
catalog in 1764.