Deep sky · Globular cluster in Hercules · M 13 · NGC 6205
M 13
Great Star Cluster in Hercules
The Great Globular Cluster in Hercules: several hundred thousand stars in a ball 150 light-years across — and the target of humanity’s first deliberate message to the stars.
- Type
- Globular cluster
- Designations
- M 13 · NGC 6205
- Constellation
- Hercules
- Apparent magnitude
- 5.8
- Apparent size
- 20′ × 8′
- Position (J2000)
- RA 16h 42m · Dec +36° 28′
History
Edmond Halley came across it in 1714 and wrote that it “shows itself to the naked eye when the sky is serene and the Moon absent.”
History
In 1974 the Arecibo radio telescope beamed a picture message towards it: numbers, DNA, a human figure. It will arrive in about 25,000 years.