NGC 6496

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NGC 6496
Final6496.jpg
Observation data
Class XII[1]
Right ascension 17h 59m 03.68s[2]
Declination −44° 15′ 57.4″[2]
Distance 36.9 kly (11.3 kpc)[3]
Physical characteristics
Mass 8.2×104[4] M
Metallicity –0.70[5] dex
Estimated age 12.42 Gyr[5]
See also: Globular cluster, List of globular clusters

NGC 6496 is a globular cluster which is in the direction of the bulge and putative members of this subgroup,[clarification needed] based on observations collected with the WFPC2 on board the Hubble Space Telescope. NGC 6496 was originally believed[who?] to be a member of the disc system of GC, but scientists questioned this classification. It was instead suggested[who?] that NGC 6496, together with two other clusters, NGC 6624 and NGC 6637, could be halo clusters with strongly inclined orbits. NGC 6496 lies in the Southern sky at RA=17:59:03.68 and Dec=-44:15:57.4.[6]

The first CMD presented of NGC 6496 had photometry reaching 2 mag below the horizontal branch, disclosing for the first time the usual red arm of the metal-rich clusters. The extinction towards NGC 6496 is uncertain, with estimates ranging between E(B-V) = 0.09 and E(B-V) = 0.24.[7]

References[edit]

  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. ^ 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. ^ Marks, Michael; Kroupa, Pavel (August 2010), "Initial conditions for globular clusters and assembly of the old globular cluster population of the Milky Way", Monthly Notices of the Royal Astronomical Society 406 (3): 2000–2012, arXiv:1004.2255, Bibcode:2010MNRAS.406.2000M, doi:10.1111/j.1365-2966.2010.16813.x.  Mass is from MPD on Table 1.
  5. ^ 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, arXiv:1001.4289, Bibcode:2010MNRAS.404.1203F, doi:10.1111/j.1365-2966.2010.16373.x. 
  6. ^ Richtler, T; Grebel, E (1994). "The cases of the "disk" globular clusters NGC 6496, NGC 6624, and NGC 6637". Astronomy and Astrophysics 290: 412–420. 
  7. ^ Armandroff, T. "Color-magnitude diagrams for six metal-rich, low-latitude globular clusters". Astronomical Journal 96 (1988). ISSN 0004-6256.