M13 - Hercules Cluster

M 13 was discovered in 1714 by Edmund Halley. The large globular cluster in the constellation Hercules is visible to the naked eye. It is about 26,000 light years away. More than 1,000,000 stars are concentrated in a region of about 160 light years diameter. The cluster has 600,000 times the mass of our Sun. The blue stars are so-called "blue stragglers". They may be the result of mergers of the old main-sequence stars of the cluster.

The galaxy North-east from M 13 is NGC 6207 an Sc-type spiral, 46 Million light years away.