You may recall from my from last week that I mentioned a nearby star cluster. It is the famous Double Cluster, as seen in the attached picture, and it’s exactly what its name implies, two clusters of stars.
The Double Cluster is 7,000 light years away*, each cluster is 80 light years across, and contain 100 or more stars per cluster. From a very dark viewing location it can be seen with the un-aided eye as a small hazy patch of light, but binoculars or a telescope are needed to reveal it as a true star cluster.
Star clusters form from the gravitational collapse of huge gas clouds. The Double Cluster is just one of thousands of star clusters sprinkled throughout our night sky. Some star clusters contain random star patterns that earn them unique names like the Wild Duck cluster, or ET the Extraterrestrial. But truth be told, all have their own unique beauty, and all star clusters help us learn about the star formation process.
This picture of the Double Cluster was taken at the Mary Aloysia Hardey Observatory, located at the Convent of the Sacred Heart in Greenwich.
*1 light year equals about 6 trillion miles (your miles may vary).