Messier Index/M9

Messier 9 or M9 (also designated NGC 6333) is a w:globular cluster in the w:constellation of w:Ophiuchus. It was discovered by w:Charles Messier in w:1764.

Messier object 009.jpg
Messier 9, from 2MASS
Observation data (J2000 epoch)
Class VIII
Constellation Ophiuchus
Right ascension 17h 19m 11.78s[1]
Declination -18° 30′ 58.5″[1]
Distance 25.8 kly (7.9 kpc)
Apparent magnitude (V) +8.42[1]
Apparent dimensions (V) 12′.0
Physical characteristics
Mass kg ( M)
Radius 45 ly
Other designations NGC 6333[1]

M9 is one of the nearer globular clusters to the center of the w:Milky Way Galaxy with a distance of around 5,500 w:light-years. Its distance from w:Earth is 25,800 light-years.

The total w:luminosity of this cluster is around 120,000 times that of the w:Sun, the w:absolute magnitude being -8.04. The brightest individual w:stars in M9 are of w:apparent magnitude 13.5, making them visible in moderately sized w:telescopes. There have been 13 w:variable stars found in M9.

Nearby, at about 80' to the northeast of M9 is the dimmer globular cluster w:NGC 6356, while at about 80' to the southeast is the globular w:NGC 6342.

External links


  1. a b c d "SIMBAD Astronomical Database". Results for NGC 6333. Retrieved 2006-11-15.