NGC 6558

NGC 6558
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	${\displaystyle {\begin{smallmatrix}\left[{\ce {Fe}}/{\ce {H}}\right]\end{smallmatrix}}}$ = -1.32 [3] dex
Other designations	Cr 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

1. "NGC 6558". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 8 January 2017.
2. "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". Astronomy and Astrophysics. 690. arXiv: 2407.15918 . Bibcode:2024A&A...690A..37S. doi:10.1051/0004-6361/202450795. 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).

External links

• Media related to NGC 6558 at Wikimedia Commons
• NGC 6558