A spectacular new photo shows a cluster of stars whose brightest objects form a triangle that has been likened to a flock of ducks in flight.
The European Southern Observatory's La Silla Observatory in Chile captured the beautiful image of Messier 11, also known as NGC 6705 or the Wild Duck Cluster, revealing the blue stars of one of the most star-rich open clusters known. You can see a Space.com video tour of Messier 11, which we set to the song "The Leaves" by the band Super 400.
Stellar clusters are groups of loosely packed stars that formed from the same cloud of gas. As a result of their shared birth conditions, stars within a cluster tend to have similar ages and chemical compositions. Clusters are thus good testing grounds for theories of stellar evolution.
The Wild Duck Cluster lies approximately 6,000 light-years away from Earth in the constellation of Scutum (The Shield). It is one of the most star-rich and compact open clusters, boasting nearly 3,000 stars within its 20-light-year diameter. Most open clusters such as Messier 11 lie within the arms of spiral galaxies, or inside the denser parts of irregular galaxies, where star formation continues.
Because the stars inside open clusters aren’t tightly packed, they only have loose gravitational ties with one another. Individual stars often find themselves ejected from the cluster when objects in their celestial neighborhood interact with them. The Wild Duck Cluster is already at least 250 million years old, so it will likely break up in the next few million years, researchers said.
The cluster is visible with binoculars and small telescopes, but remains small and faint. A 4-inch telescope should resolve it somewhat, while an 8-inch or larger telescope will reveal hundreds of diamond-like points of light within M11. But it took the Wild Field Imager on the ESO's 2.2-meter (86 inches) telescope at La Silla to capture the full beauty of the Wild Duck Cluster.