M13 (NGC 6205) - Hercules Cluster
Messier M13 (NGC 6205), also known as the Hercules Cluster, is a globular cluster located in the constellation Hercules, in the Galactic Center of the Milky Way Galaxy. in the Local Group of galaxies.
Messier M13 is best viewed during mid-summer, is magnitude 5.9*, and can be viewed with naked eye (just barely). It is 16.6' in size. For reference, the full moon is 30' (arc minutes) in size.
* The naked eye can see up to magnitude 8 objects under ideal dark sky conditions.
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