Messier 55
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Observation data: J2000 epoch | |
---|---|
Class: | XI |
Constellation: | Sagittarius |
Right ascension: | 19h 39m 59.40s[1] |
Declination: | -30° 57′ 43.5″[1] |
Distance: | 17.3 kly[citation needed] (5.3 kpc) |
Apparent magnitude (V): | +7.42[1] |
Apparent dimensions (V): | 19′.0 |
Physical characteristics | |
Mass: | ( M☉) |
Radius: | 48 ly[2] |
VHB: | |
Estimated age: | |
Notable features: | |
Other designations: | M55, NGC 6809, GCl 113[1] |
See also: Globular cluster, List of globular clusters |
Messier 55 (also known as M55 or NGC 6809) is a globular cluster in the constellation Sagittarius. It was discovered by Nicolas Louis de Lacaille in 1751 and catalogued by Charles Messier in 1778. M55 is at a distance of about 17,300 light-years away from Earth. Only about half a dozen variable stars have been discovered in M55.