Deep space
Hercules Cluster
Globular cluster · M13
The great northern globular
A ball of several hundred thousand ancient stars, visible in binoculars on the Keystone of Hercules.
In your sky
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Key facts
Distance
~22,200 light-years
Stars
~300,000
Apparent mag.
+5.8
Diameter
~145 light-years
Did you know
- The 1974 Arecibo radio message was beamed toward it.
- Edmond Halley discovered it in 1714.
- Its stars are among the oldest in the galaxy.
