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NGC 6522

NGC 6522
N6522 32ins.jpg
32 inch telescope
NGC 6528 (lower left) and NGC 6522 (upper right)
Observation data (J2000 epoch)
Constellation Sagittarius
Right ascension 18h 3m 34.1s
Declination −30° 2′ 2.3″
Distance 25.1 kly (7.7 kpc)
Apparent magnitude (V) 10.5
Apparent dimensions (V) 2'
Physical characteristics
Mass 3.00×105 M
Metallicity  = –1.34dex
Estimated age 12.0 Gyr
See also: Globular cluster, List of globular clusters

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.


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Wikipedia

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