Globular Star Cluster M13
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Globular Star Cluster M13 |
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Stars in Hercules
| M13
| M92
| NGC 6058
| NGC 6210
| NGC 6229
M13 is sometimes called the Great Hercules Star Cluster, which gives you the immediate idea that this is something unusual and spectacular. This is true on both counts; this is finest spherical or "globular" star cluster north of the celestial equator, being naked eye visible from dark locations at magnitude 5.7. Spanning 23 arc minutes, this ball of countless stars is nearly as large in out sky as the full moon - despite being about 20,000 light years away! In binoculars, the cluster is a small hazy "star" located on the west side of the central "keystone" asterism in Hercules; small telescopes reveal what looks like a comet at first, a softly glowing round ball of light fading at the edges. Larger amateur instruments under dark skies show hundreds of individual stars glittering across the face of M13, and one can only imagine the splendor of the sky for a planet around one of its stars. While given its present designation by Charles Messier in 1764, the cluster was first mentioned by the famed Edmund Halley in 1715.
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