NGC 6522 is a globular cluster in the constellation Sagittarius. It is apparent magnitude 8.3, and diameter 16.4 arc minutes, 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.[1][3]
NGC 6522 | |
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Observation data (J2000 epoch) | |
Constellation | Sagittarius |
Right ascension | 18h 03m 34.1s[1] |
Declination | −30° 02′ 2.3″[1] |
Distance | 25.1 kly (7.7 kpc)[2] |
Apparent magnitude (V) | 8.3[3] |
Apparent dimensions (V) | 16.4'[3] |
Physical characteristics | |
Mass | 3.00×105[2] M☉ |
Metallicity | |
Estimated age | 12.0 Gyr[4] |
Other designations | GCl 82, C 1800-300[1] |
See also: Globular cluster, List of globular clusters |
NGC 6522 is possibly the oldest star cluster in the Milky Way,[5] with an age of more than 12 billion years.[6]
New General Catalogue 6500 to 6999 | |
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