NGC 4833

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NGC 4833
Observation data: J2000 epoch
Class: VIII
Constellation: Musca
Right ascension: 12h 59m 34.98s[1]
Declination: -70° 52′ 28.6″[1]
Distance: 21.2 kly[citation needed] (6.5 kpc)
Apparent magnitude (V): +7.79[1]
Apparent dimensions (V): 13′.5
Physical characteristics
Mass: ( M)
Radius: 42 ly[2]
VHB:
Estimated age: 15 Gyr[citation needed]
Notable features:
Other designations: GCl 21,[1] Lacaille I.4
Dunlop 164, Bennett 56
See also: Globular cluster, List of globular clusters


NGC 4833 is a globular cluster discovered by Abbe Lacaille during his 1751-1752 journey to South Africa, and catalogued in 1755. It was subsequently observed and catalogued by James Dunlop and Sir John Herschel whose instruments could resolve it into individual stars.

The globular cluster is situated in the very southerly constellation Musca at a distance of 21,200 light years from earth. It is partially obscured by a dusty region of the galactic plane. After corrections for the reddening by dust, evidence was obtained that it is in the order of 2 billion years older than globular clusters M5 or M92.

[edit] References

  1. ^ a b c d SIMBAD Astronomical Database. Results for NGC 4833. Retrieved on 2006-11-17.
  2. ^ distance × sin( diameter_angle / 2 ) = 42 ly. radius
  1. CCD Photometry of the Globular Cluster NGC 4833 and Extinction Near the Galactic Plane, Melbourne et al, 25 September 2000, Astrophysics Journal

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[edit] See also