- Messier 55
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Messier 55 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 Radius 48 ly[2] 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.
References
- ^ a b c d "SIMBAD Astronomical Database". Results for NGC 6809. http://simbad.u-strasbg.fr/Simbad. Retrieved 2006-11-16.
- ^ distance × sin( diameter_angle / 2 ) = 48 ly. radius
External links
- Messier 55, SEDS Messier pages
- Messier 55, Galactic Globular Clusters Database page
- Messier 55 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images
Coordinates:
19h 39m 59.40s, −30° 57′ 43.5″
Messier objects List M1 · M2 · M3 · M4 · M5 · M6 · M7 · M8 · M9 · M10 · M11 · M12 · M13 · M14 · M15 · M16 · M17 · M18 · M19 · M20 · M21 · M22 · M23 · M24 · M25 · M26 · M27 · M28 · M29 · M30 · M31 · M32 · M33 · M34 · M35 · M36 · M37 · M38 · M39 · M40 · M41 · M42 · M43 · M44 · M45 · M46 · M47 · M48 · M49 · M50 · M51 · M52 · M53 · M54 · M55 · M56 · M57 · M58 · M59 · M60 · M61 · M62 · M63 · M64 · M65 · M66 · M67 · M68 · M69 · M70 · M71 · M72 · M73 · M74 · M75 · M76 · M77 · M78 · M79 · M80 · M81 · M82 · M83 · M84 · M85 · M86 · M87 · M88 · M89 · M90 · M91 · M92 · M93 · M94 · M95 · M96 · M97 · M98 · M99 · M100 · M101 · M102 · M103 · M104 · M105 · M106 · M107 · M108 · M109 · M110See also Book:Messier objects ·
Category:Messier objects
Portal:Astronomy
Categories:- Globular clusters
- Sagittarius constellation
- Messier objects
- NGC objects
- Star cluster stubs
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