Messier 68

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This article is about the astronomical object. For other uses, see M68 (disambiguation).
Messier 68
Messier 68 Hubble WikiSky.jpg
M68 from Hubble Space Telescope in 2008; 3.32′ view
Credit: NASA/STScI/WikiSky
Observation data (J2000 epoch)
Class X[1]
Constellation Hydra
Right ascension 12h 39m 27.98s[2]
Declination –26° 44′ 38.6″[2]
Distance 33.6 kly (10.3 kpc)[3]
Apparent magnitude (V) +9.67[4]
Apparent dimensions (V) 11′.0
Physical characteristics
Mass 2.23×105[3] M
Radius 53 ly[5]
Metallicity –2.23[3] dex
Estimated age 11.2 Gyr[6]
Notable features Relatively metal poor.[3]
Other designations M68, NGC 4590, GCl 20[4]
See also: Globular cluster, List of globular clusters

Messier 68 (also known as M68 or NGC 4590) is a globular cluster in the Hydra constellation. It was discovered by Charles Messier in 1780. M68 is at a distance of about 33,000 light-years away from Earth.

A 2012 view of M68 from the Wide Field Camera of Hubble’s Advanced Camera for Surveys


  1. ^ Shapley, Harlow; Sawyer, Helen B. (August 1927), "A Classification of Globular Clusters", Harvard College Observatory Bulletin (849): 11–14, Bibcode:1927BHarO.849...11S 
  2. ^ a b Goldsbury, Ryan; et al. (December 2010), "The ACS Survey of Galactic Globular Clusters. X. New Determinations of Centers for 65 Clusters", The Astronomical Journal 140 (6): 1830–1837, arXiv:1008.2755, Bibcode:2010AJ....140.1830G, doi:10.1088/0004-6256/140/6/1830. 
  3. ^ a b c d Boyles, J.; et al. (November 2011), "Young Radio Pulsars in Galactic Globular Clusters", The Astrophysical Journal 742 (1): 51, arXiv:1108.4402, Bibcode:2011ApJ...742...51B, doi:10.1088/0004-637X/742/1/51. 
  4. ^ a b "SIMBAD Astronomical Database". Results for NGC 4590. Retrieved 2006-11-17. 
  5. ^ distance × sin( diameter_angle / 2 ) = 53 ly. radius
  6. ^ Sollima, A.; et al. (April 2008), "The correlation between blue straggler and binary fractions in the core of Galactic globular clusters", Astronomy and Astrophysics 481 (3): 701–704, arXiv:0801.4511, Bibcode:2008A&A...481..701S, doi:10.1051/0004-6361:20079082 

External links[edit]

Coordinates: Sky map 12h 39m 28.01s, −26° 44′ 34.9″