NGC 6558

NGC 6558 is a globular cluster, located about 24,000 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
The globular cluster NGC 6558 Credit: HST
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]

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