Messier 75

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Messier 75
Observation data: J2000 epoch
Class: I
Constellation: Sagittarius
Right ascension: 20h 06m 04.75s[1]
Declination: -21° 55′ 16.2″[1]
Distance: 67.5 kly[citation needed] (20.7 kpc)
Apparent magnitude (V): +9.18[1]
Apparent dimensions (V): 6′.8
Physical characteristics
Mass: ( M)
Radius: 67 ly[2]
VHB:
Estimated age:
Notable features:
Other designations: M75, NGC 6864, GCl 116[1]
See also: Globular cluster, List of globular clusters


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

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

[edit] External links

[edit] References

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