NGC 4833

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NGC 4833
A sky full of stars NGC 4833.jpg
NGC 4833 is one of the over 150 globular clusters known to reside within the Milky Way.[1]
Credit: ESA/Hubble and NASA
Observation data (J2000 epoch)
Class VIII[2]
Constellation Musca
Right ascension 12h 59m 33.92s[3]
Declination –70° 52′ 35.4″[3]
Distance 21.5 kly (6.6 kpc)[4]
Apparent magnitude (V) +7.79[5]
Apparent dimensions (V) 13′.5
Physical characteristics
Mass 4.10×105[4] M
Radius 42 ly[6]
Metallicity  = –1.71[7] dex
Estimated age 12.54 Gyr[7]
Other designations GCl 21,[5] Lacaille I.4
Dunlop 164, Bennett 56
See also: Globular cluster, List of globular clusters

NGC 4833 (also known as Caldwell 105) 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.

Gallery[edit]

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References[edit]

  1. ^ "A sky full of stars". www.spacetelescope.org. Retrieved 1 August 2016. 
  2. ^ Shapley, Harlow; Sawyer, Helen B. (August 1927), "A Classification of Globular Clusters", Harvard College Observatory Bulletin (849): 11–14, Bibcode:1927BHarO.849...11S. 
  3. ^ 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, Bibcode:2010AJ....140.1830G, arXiv:1008.2755Freely accessible, doi:10.1088/0004-6256/140/6/1830. 
  4. ^ a b Boyles, J.; et al. (November 2011), "Young Radio Pulsars in Galactic Globular Clusters", The Astrophysical Journal, 742 (1): 51, Bibcode:2011ApJ...742...51B, arXiv:1108.4402Freely accessible, doi:10.1088/0004-637X/742/1/51. 
  5. ^ a b "SIMBAD Astronomical Object Database". Results for NGC 4833. Retrieved 2006-11-17. 
  6. ^ distance × tan( diameter_angle / 2 ) = 42 ly. radius
  7. ^ a b Forbes, Duncan A.; Bridges, Terry (May 2010), "Accreted versus in situ Milky Way globular clusters", Monthly Notices of the Royal Astronomical Society, 404 (3): 1203–1214, Bibcode:2010MNRAS.404.1203F, arXiv:1001.4289Freely accessible, doi:10.1111/j.1365-2966.2010.16373.x. 
  1. CCD Photometry of the Globular Cluster NGC 4833 and Extinction Near the Galactic Plane, Melbourne et al., 25 September 2000, Astrophysical Journal

External links[edit]

Coordinates: Sky map 12h 59m 34.98s, −70° 52′ 28.6″