Messier 13
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| Messier 13 | |
 Messier 13 by Hubble Space Telescope; 3.3′ view Credit: NASA/STScI/WikiSky |
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| Observation data (J2000 epoch) | |
|---|---|
| Class | V |
| Constellation | Hercules |
| Right ascension | 16h 41m 41.44s[1] |
| Declination | +36° 27′ 36.9″[1] |
| Distance | 25.1 kly () |
| Apparent magnitude (V) | +5.8[1] |
| Apparent dimensions (V) | 23′ |
| Physical characteristics | |
| Mass | 1036 kg (6×105 [2] M ) |
| Radius | 84 ly[3] |
| Estimated age | 1.4 × 1010 yr |
| Notable features | one of the best well-known clusters of the northern hemisphere |
| Other designations | NGC 6205[1] |
| See also: Globular cluster, List of globular clusters | |
Messier 13 or M13 (also designated NGC 6205 and sometimes called the Great Globular Cluster in Hercules or the Hercules Globular Cluster) is a globular cluster in the constellation of Hercules.
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[edit] Discovery and visibility
M13 was discovered by Edmond Halley in 1714, and catalogued by Charles Messier on June 1, 1764.
It is located at right ascension 16h 41.7m and declination +36° 28'. With an apparent magnitude of 5.8, it is barely visible with the naked eye on a very clear night. Its diameter is about 23 arc minutes and it is readily viewable in small telescopes. Nearby is NGC 6207, a 12th magnitude edge-on galaxy that lies 28 arc minutes directly north east. A small galaxy, IC 4617, lies halfway between NGC 6207 and M13, north-northeast of the large globular's center.
[edit] Characteristics
M13 is about 145 light-years in diameter, and it is composed of several hundred thousand stars, the brightest of which is the variable star V11 with an apparent magnitude of 11.95. M13 is 25,100 light-years away from Earth.
[edit] Arecibo message
The Arecibo message of 1974, designed to communicate the existence of human life to hypothetical extraterrestrials, was transmitted toward M13. The reason was that with a higher star density, the chances of a life harboring planet with intelligent life forms, were higher.
[edit] Literary references
- The science fiction novellas "Sucker Bait" by Isaac Asimov and "Question and Answer" by Poul Anderson take place on Troas, a world within M13.
- In the science fiction series Perry Rhodan, M13 is the location of Arkon, the home world of the race of Arkonides.
- In author Dan Simmon's Hyperion Cantos the Hercules cluster is where Earth was secretly moved to after it was supposedly destroyed.
- In The Sirens of Titan, Kurt Vonnegut writes "Every passing hour brings the Solar System forty-three thousand miles closer to Globular Cluster M13 in Hercules -- and still there are some misfits who insist that there is no such thing as progress."
[edit] See also
[edit] External links
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Wikimedia Commons has media related to: Category:Messier 13 |
- Messier 13, SEDS Messier pages
- Messier 13, Galactic Globular Clusters Database page
- Messier 13, High-resolution LRGB image based on 2 hrs total exposure
- Messier 13, Image by Waid Observatory
- NightSkyInfo.com - M13, the Hercules Globular Cluster
- Photometric study of the V2 cepheid in M13
- Period, Amplitude and Light Curve of V38 in M13
- Great Globular Cluster in Hercules (Messier 13/NGC 6205)
- M13 images taken by Stargazer-Observatory
- M13
- Messier 13 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images
[edit] References
- ^ a b c d "SIMBAD Astronomical Database". Results for NGC 6205. http://simbad.u-strasbg.fr/Simbad. Retrieved on 2006-11-15.
- ^ Leonard, Peter J. T.; Richer, Harvey B.; Fahlman, Gregory G.. "The mass and stellar content of the globular cluster M13". http://adsabs.harvard.edu/abs/1992AJ....104.2104L.
- ^ distance × sin( diameter_angle / 2 ) = 84 ly. radius
Coordinates: 
16h 41m 41.44s, +36° 27′ 36.9″
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