NGC 4833
| NGC 4833 | |
|---|---|
 NGC 4833 is one of the over 150 globular clusters known to reside within the Milky Way.[1] | |
| 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′[6] |
| Physical characteristics | |
| Absolute magnitude | −8.16[7] |
| Mass | 4.10×105[4] M☉ |
| Radius | 42 ly[8] |
| Metallicity | = –2.02[7] dex |
| Estimated age | 12.54 Gyr[9] |
| Other designations | NGC 4833, Caldwell 105, GCl 21,[5] Lacaille I.4, Dunlop 164, Bennett 56 |
![{\displaystyle {\begin{smallmatrix}\left[{\ce {Fe}}/{\ce {H}}\right]\end{smallmatrix}}}](https://wikimedia.riteme.site/api/rest_v1/media/math/render/svg/4c0821bd80891e071c08e7c7ee8e022baedf522c)
NGC 4833 is a globular cluster discovered by Abbe Lacaille during his 1751-1752 journey to South Africa, and catalogued in 1755.[10] It was subsequently observed and catalogued by James Dunlop and Sir John Herschel whose instruments could resolve it into individual stars.[6]
The globular cluster is situated in the very southerly constellation Musca[6] at a distance of 21,500 light years from Earth.[4] It is located near the Coalsack Nebula and is partially obscured by this dusty region of the galactic plane.[7] 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.[11]
This is a massive, metal-poor globular cluster that shows evidence for multiple generations of stars.[12] It is an old halo cluster of the Oosterhoff type II. The orbit of the cluster through the galaxy is very eccentric, with an eccentricity of 0.84 that carries it close to the galactic center. The cluster has likely lost a significant portion of its original mass due to interactions with the galactic bulge.[7]
A 2012 survey for variable stars identified six SX Phe, two eclipsing binaries (including a W UMa), and 19 RR Lyr variables.[13][14]
See also
[edit]References
[edit]- ^ "A sky full of stars", www.spacetelescope.org, retrieved 1 August 2016.
- ^ Shapley, Harlow; Sawyer, Helen B. (August 1927), "A Classification of Globular Clusters", Harvard College Observatory Bulletin, 849 (849): 11–14, Bibcode:1927BHarO.849...11S.
- ^ 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, S2CID 119183070.
- ^ a b c 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, S2CID 118649860.
- ^ a b "NGC 4833". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2006-11-17.
- ^ a b c O'Meara, Stephen James (2016), Deep-Sky Companions: The Caldwell Objects, Cambridge University Press, pp. 480–482, ISBN 9781316033531.
- ^ a b c d Carretta, E.; et al. (April 2014), "The extreme chemistry of multiple stellar populations in the metal-poor globular cluster NGC 4833", Astronomy & Astrophysics, 564, id. A60, arXiv:1401.7325, Bibcode:2014A&A...564A..60C, doi:10.1051/0004-6361/201323321.
- ^ distance × tan( diameter_angle / 2 ) = 42 ly. radius
- ^ 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, arXiv:1001.4289, Bibcode:2010MNRAS.404.1203F, doi:10.1111/j.1365-2966.2010.16373.x, S2CID 51825384.
- ^ Jones, K. G. (March 1969), "The search for the nebulae - VI", Journal of the British Astronomical Association, 79: 213–222, Bibcode:1969JBAA...79..213J.
- ^ Melbourne, Jason; et al. (December 2000), "CCD Photometry of the Globular Cluster NGC 4833 and Extinction Near the Galactic Plane", The Astronomical Journal, 120 (6): 3127–3138, arXiv:astro-ph/0009401, Bibcode:2000AJ....120.3127M, doi:10.1086/316869.
- ^ Carretta, Eugenio (May 2021), "Potassium abundances in multiple stellar populations of the globular cluster NGC 4833", Astronomy & Astrophysics, 649, id. A154, arXiv:2103.10441, Bibcode:2021A&A...649A.154C, doi:10.1051/0004-6361/202140684.
- ^ Darragh, A. N.; Murphy, B. W. (July 2012), "New SX Phoenicis Variables in the Globular Cluster NGC 4833", Journal of the Southeastern Association for Research in Astronomy, 6: 72–77, arXiv:1205.1025, Bibcode:2012JSARA...6...72D.
- ^ Demers, S.; Wehlau, A. (August 1977), "Variable stars of NGC 4833", Astronomical Journal, 82: 620–625, Bibcode:1977AJ.....82..620D, doi:10.1086/112095.
Further reading
[edit]- Roederer, Ian U.; Thompson, Ian B. (June 2015), "Detailed abundances of 15 stars in the metal-poor globular cluster NGC 4833", Monthly Notices of the Royal Astronomical Society, 449 (4): 3889–3910, arXiv:1503.03079, Bibcode:2015MNRAS.449.3889R, doi:10.1093/mnras/stv546.
- Kopacki, Grzegorz (February 2014), "Wide-field variability survey of the globular cluster NGC 4833", Precision Asteroseismology, Proceedings of the International Astronomical Union, IAU Symposium, vol. 301, pp. 441–442, arXiv:1401.4822, Bibcode:2014IAUS..301..441K, doi:10.1017/S1743921313014956.
- Samus, N.; et al. (March 1995), "A new photographic C-M diagram for NGC 4833.", Astronomy and Astrophysics Supplement, 109: 479–486, Bibcode:1995A&AS..109..479S.
- Wright, Frances W. (1946), McLaughlin, Dean B. (ed.), "Eleven variable stars in the globular cluster NGC 4833", Publications of the American Astronomical Society, 10, Published by the AAS: 264, Bibcode:1946PAAS...10..264W.
External links
[edit]
Wikimedia Commons has media related to NGC 4833.
- Basic information and data
- Photographed by the Antilhue amateur astronomical observatory
- CCD Photometry of the Globular Cluster NGC 4833 and Extinction Near the Galactic Plane
- Position relative to nearby cluster NGC 4372
- NGC 4833 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images
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