Universe Guide

Home / Facts / Star Cluster

Messier 21 (M21, NGC6531)

Messier 21 is an open cluster object of interest in space. It lies at a distance of 4.25 light years away in the constellation of Sagittarius. It is referred to as M(21) when it was catalogued by Charles Messier in 18th - 19th Century France. It is referred to as NGC(6531) in the New General Catalogue. This is a list of deep space objects that was compiled by John Louis Emil Dreyer in 1888 in an update to John Herschel earlier catalogue. Messier 21 was discovered in 1764 by Charles Messier. The Open Cluster's location is 18:04.6 (R.A.) and -22:30 (Dec.). Its Visual Brightness is a 6.5 Magnitude and has an apparent magnitude of 7 with an apparent dimension of 13.0 .

(M21,NGC6531) is a open cluster. It was discovered in 1764 by Charles Messier. It's location is RA(18:04.6), Dec(-22:30) and its distance is calculated 4.25 light years away. Its visual Brightness is 6.5. Its apparent dimensions measured in arcmins is 13.0.

Fact File

NameMessier 21
TypeOpen Cluster
Messier Id21
NGC Id6531
TypeOpen Cluster
Right Ascension18:04.6
Distance (Lt.Yr)4.25
Visual Brightness6.5
Apparent Dimension13.0
Apparent Magnitude7
Year of Discovery1764
DiscovererCharles Messier