NGC 6352

NGC 6352 (also known as Caldwell 81) is a globular cluster of stars in the southern constellation of Ara, located approximately 18.3 kly[3] from the Sun. It was discovered by Scottish astronomer James Dunlop on May 14, 1826.[10] The cluster has a Shapley–Sawyer Concentration Class of XI:.[1] A telescope with a 15 cm (5.9 in) aperture is required to resolve the stars within this loose cluster.[4]

NGC 6352
Observation data (J2000 epoch)
Class	XI:[1]
Constellation	Ara
Right ascension	17^h 25^m 29.11^s[2]
Declination	–48° 25′ 19.8″[2]
Distance	18.3 kly (5.6 kpc)[3]
Apparent magnitude (V)	+7.8[4]
Apparent dimensions (V)	7′.1[5]
Physical characteristics
Mass	3.7×10^4[6] M☉
Tidal radius	10.5″[7]
Metallicity	${\displaystyle {\begin{smallmatrix}\left[{\ce {Fe}}/{\ce {H}}\right]\end{smallmatrix}}}$ = –0.70[8] dex
Estimated age	12.67 Gyr[8]
Other designations	Caldwell 81, Cr 328, NGC 6352[9]

This cluster is about 12.67[8] billion years old with two distinct stellar populations; the second generation is only around 10 million years younger than the first.[3] It lies approximately 13 kly (4 kpc) from the galactic center and 1.6 kly (0.5 kpc) from the galactic plane.[11] The orbital motion of this cluster through the Milky Way suggests it is a member of the bulge or disk population.[12] It is relatively metal-rich for an object of this class,[3] having a metallicity of –0.70.[8] The core radius is 49.8″[3] and the tidal radius is 10.5″.[7]

References

1. Shapley, Harlow; Sawyer, Helen B. (August 1927), "A Classification of Globular Clusters", Harvard College Observatory Bulletin, 849 (849): 11–14, Bibcode:1927BHarO.849...11S.
2. 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. Libralato, Mattia; et al. (March 2019), "The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. XVIII. Proper-motion Kinematics of Multiple Stellar Populations in the Core Regions of NGC 6352", The Astrophysical Journal, 873 (2): 12, arXiv:1902.02787, Bibcode:2019ApJ...873..109L, doi:10.3847/1538-4357/ab0551, 109.
4. Dunlop, Storm (2005). Atlas of the Night Sky. Harper Collins. ISBN 978-0-00-717223-8.
5. O'Meara, Stephen James. Deep Sky Companions: The Caldwell Objects. p. 324. ISBN 0-521-82796-5.
6. 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 M_PD on Table 1.
7. Johnston, H. M.; et al. (May 1996), "ROSAT observations of ten globular clusters with large core radii.", Astronomy and Astrophysics, 309: 116–122, Bibcode:1996A&A...309..116J.
8. 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.
9. "NGC 6352". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-02-26.
10. Seligman, Courtney. "New General Catalogue objects: NGC 6350 - 6399". cseligman.com. Retrieved 2020-09-20.
11. Fullton, L. K.; et al. (August 1995), "A VIC Color-Magnitude Diagram of the Globular Cluster NGC 6352 From Hubble Space Telescope Planetary Camera Observations", Astronomical Journal, 110: 652, Bibcode:1995AJ....110..652F, doi:10.1086/117552.
12. Wagner-Kaiser, R.; et al. (July 2016). "Bayesian Analysis of Two Stellar Populations in Galactic Globular Clusters. II. NGC 5024, NGC 5272, and NGC 6352". The Astrophysical Journal. 826 (1): 18. arXiv:1604.06074. Bibcode:2016ApJ...826...42W. doi:10.3847/0004-637X/826/1/42. 42.

External links

• Media related to NGC 6352 at Wikimedia Commons