BLACK DOG OBSERVATORY

M4 (NGC6121) The Cat's Eye

This may be the nearest Globular Cluster to the Sun, eclipsing NGC6397 (also on this page) in the constellation Ara. It is not as spectaular as it could be as it is obscured by dust which dims and reddens its light. It's 58 light years diameter and 7200 light years away. In 2003 a planet estimated to be 13 billion years old was found in this cluster. It is by far the oldest planet known and the first to be found in a Globular Cluster.