An image of another Messier open cluster, M21, has been uploaded

Hi all,

An image of another open cluster, Messier 21, has been uploaded. This is a very young cluster (less than 5 million years old) and its stars seem to belong to the Sagittarius OB1 Association. You can find the image and some more information at:

Messier 21. NGC 6531

Enjoy,
Josep