NGC 6558 is a globular cluster, located about 24,000[4] 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.
NGC 6558 | |
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The globular cluster NGC 6558 imaged by the Hubble Space Telescope | |
Observation data (J2000 epoch) | |
Class | V |
Constellation | Sagittarius |
Right ascension | 18h 10m 18.38s[1] |
Declination | −31° 45′ 48.6″[1] |
Distance | 24.1 kly (7.4 kpc)[1] |
Apparent magnitude (V) | 11.29[1] |
Physical characteristics | |
Radius | 5.2' x 5.2'[2] |
Metallicity | = -1.32[3] dex |
Other designations | Cr 368, GCl 89, ESO 456-62, VDBH 259[1] |
It is located 1.5 degrees south-southeast of Gamma2 Sagittarii.
References
edit- ^ a b c d e "NGC 6558". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 8 January 2017.
- ^ a b "NGC 6558". Retrieved 8 January 2016.
- ^ "A Galactic Globular Clusters Database: NGC 6558". Retrieved 8 January 2017.
- ^ In an article appeared on arXiv, S. O. Souza et alii: "Combined Gemini-South and HST photometric analysis of the globular cluster NGC 6558. The age of the metal-poor population of the Galactic Bulge" would correct the distance as far as 27,400 ly. DOI: 10.48550/arxiv.2407.15918 (2024).
External links
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