Constellation Ophiuchus Declination −23° 54′ 31.5″ Apparent magnitude (V) 7.40 | Right ascension 17 38 36.93 Distance 24.450 Apparent dimensions (V) 4.8' | |
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NGC 6401 is a globular cluster in the constellation Ophiuchus. William Herschel discovered this star cluster in 1784 with his 47 cm telescope, but mistakenly believed it to be a bright nebula. Later his son, John Herschel, was to make the same error because the technology of the day was insufficient to allow the individual stars to be resolved visually.
References
NGC 6401 Wikipedia(Text) CC BY-SA