Declination −30° 2′ 2.3″ Apparent magnitude (V) 10.5 | Right ascension 18 3 34.1 Distance 25.1 kly (7.7 kpc) Apparent dimensions (V) 2' | |
 | ||
NGC 6522 is a globular cluster in the constellation Sagittarius. It is apparent magnitude 10.5, and diameter 2 arc seconds, and class VI with stars 16th magnitude and dimmer. It was discovered by William Herschel on June 24, 1784. It is centered in a region of the sky known as Baade's Window.
NGC 6522 is possibly the oldest star cluster in the Milky Way, with an age of more than 12 billion years.
References
NGC 6522 Wikipedia(Text) CC BY-SA