Messier 75 (also known as M75 or NGC 6864) is a w:globular cluster in the w:constellation Sagittarius. It was discovered by w:Pierre Méchain in w:1780 and included in w:Charles Messier's catalog of w:comet-like objects that same year.

Messier 75
Observation data (w:J2000 epoch)
Right ascension20h 06m 04.75s[1]
Declination-21° 55′ 16.2″[1]
Distance67.5 kly[citation needed] (20.7 kpc)
Apparent magnitude (V)+9.18[1]
Apparent dimensions (V)6′.8
Physical characteristics
Masskg ( M)
Radius67 ly[2]
Other designationsM75, NGC 6864, GCl 116[1]

M75 is at a distance of about 67,500 w:light years away from w:Earth and its apparent size on the sky translates to a true radius of some 67 w:light years. It is classified as class I, meaning it is one of the more densely concentrated globular clusters known. The w:absolute magnitude of M75 is about -8.5 or some 180,000 more luminous than the w:Sun.

External links


  1. a b c d "SIMBAD Astronomical Database". Results for NGC 6864. Retrieved 2006-11-16.
  2. distance × sin( diameter_angle / 2 ) = 67 ly. radius