M21 Messier 21
Coordinates
- X -452
- Y -80
- Z 3898
→ Sol: ∼3,925
Neighbourhood :
- M21 Sector BM-T b4-0
- M21 Sector CH-H a25-2
- M21 Sector DQ-Y d28
- M21 Sector FQ-C a14-0
- M21 Sector HC-U c3-10
Wiki
Messier 21 or M21 (also designated NGC 6531) is an open cluster of stars in the constellation of Sagittarius. It was discovered and catalogued by Charles Messier on June 5, 1764.
M21 is a relatively young cluster of a mere 4.6 million years of age. It is tightly packed but contains about 57 stars. A few blue giant stars have been identified in the cluster, but Messier 21 is composed mainly of small dim stars. With a magnitude of 6.5, M21 is not visible to the naked eye; however, with the smallest binoculars it can be easily spotted on a dark night.
This article uses material from the Wikipedia article "Messier 21", which is released under the Creative Commons Attribution-Share-Alike License 3.0.