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NGC 6558

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NGC 6558
The globular cluster NGC 6558 imaged by the Hubble Space Telescope
Observation data (J2000 epoch)
ClassV
ConstellationSagittarius
Right ascension18h 10m 18.38s[1]
Declination−31° 45′ 48.6″[1]
Distance24.1 kly
(7.4 kpc)[1]
Apparent magnitude (V)11.29[1]
Physical characteristics
Radius5.2' x 5.2'[2]
Metallicity = -1.32[3] dex
Other designationsCr 368, GCl 89, ESO 456-62, VDBH 259[1]
See also: Globular cluster, List of globular clusters

NGC 6558 is a globular cluster, located about 24,000[4][a] light years away in the constellation Sagittarius. Its apparent magnitude is about 11 and its apparent diameter is about 10 arcminutes.[2] The globular cluster was discovered in 1784 by the astronomer William Herschel with his 18.7-inch telescope and the discovery was later catalogued in the New General Catalogue.

It is located 1.5 degrees south-southeast of Gamma2 Sagittarii.

References

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  1. ^ a b c d e "NGC 6558". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 8 January 2017.
  2. ^ a b "NGC 6558". Retrieved 8 January 2016.
  3. ^ "A Galactic Globular Clusters Database: NGC 6558". Retrieved 8 January 2017.
  4. ^ Souza, S. O.; Libralato, M.; Nardiello, D.; Kerber, L. O.; Ortolani, S.; Pérez-Villegas, A.; Oliveira, R. A. P.; Barbuy, B.; Bica, E.; Griggio, M.; Dias, B. (2024). "Combined Gemini-South and HST photometric analysis of the globular cluster NGC 6558. The age of the metal-poor population of the Galactic Bulge". arXiv:2407.15918 [astro-ph.GA]. In the literature, the heliocentric distance of NGC 6558 ranges from ∼6.3 kpc (Rich et al. 1998) to ∼8.3 kpc (Barbuy et al. 2018b).
Notes
  1. ^ The central value in the range is 7.3 kiloparsecs (24,000 ly).
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