Messier Index/M69

From Wikibooks, open books for an open world
< Messier Index
Jump to: navigation, search
Messier 69
Messier 69 Hubble WikiSky.jpg
M69 by w:Hubble Space Telescope; 3.5′ view
Credit: w:NASA/w:STScI/w:WikiSky
Observation data (w:J2000 epoch)
Class V
Constellation Sagittarius
Right ascension 18h 31m 23.23s[1]
Declination -32° 20′ 52.7″[1]
Distance 29.7 kly (9.1 kpc)
Apparent magnitude (V) +8.31[1]
Apparent dimensions (V) 9′.8
Physical characteristics
Mass kg ( M{\odot})
Radius 42 ly[2]
Other designations M69, NGC 6637, GCl 96[1]

Messier 69 (also known as M69 or NGC 6637) is a w:globular cluster in the w:constellation Sagittarius. It was discovered by w:Charles Messier in August 31, w:1780, the same night he discovered M70. At the time, he was searching for an object described by LaCaille in 1751-2 and thought he had rediscovered it, but it is unclear if LaCaille actually described M69.

M69 is at a distance of about 29,700 w:light-years away from w:Earth and has a spatial radius of 42 light-years. It is a close neighbor of w:Globular Cluster M70, 1,800 light-years separating the two objects, and both these clusters lie close to the Galactic Center. It is one of the most metal-rich globular cluster known.

0.2° view]]


External links

References

  1. a b c d "SIMBAD Astronomical Database". Results for NGC 6637. http://simbad.u-strasbg.fr/Simbad. Retrieved 2006-11-17. 
  2. distance × sin( diameter_angle / 2 ) = 42 ly. radius