Properties (19)
| Predicate | Object |
|---|---|
| gptkbp:instanceOf |
open cluster
|
| gptkbp:age |
approximately 4 million years
|
| gptkbp:associatedWith |
the_Lagoon_Nebula_(M8)_nearby
|
| gptkbp:contains |
approximately 57
|
| gptkbp:coordinates |
Right Ascension 18h 03m 30s, Declination -22° 30′ 00″
|
| gptkbp:diameter |
approximately 10 light years
|
| gptkbp:established |
gptkb:Jean-Marie_Méchain
|
| gptkbp:exhibits |
Messier catalog
|
| gptkbp:hasRecognition |
6.5
|
| https://www.w3.org/2000/01/rdf-schema#label |
Messier 21
|
| gptkbp:isLocatedIn |
gptkb:Messier's_original_catalog
|
| gptkbp:length |
approximately 4,000 light years
|
| gptkbp:lighting |
moderately bright
|
| gptkbp:locatedIn |
constellation_Sagittarius
|
| gptkbp:previouslyKnownAs |
NGC 6531
|
| gptkbp:releaseYear |
1764
|
| gptkbp:type |
stellar cluster
|
| gptkbp:visibility |
best viewed in summer months
|
| gptkbp:visitedBy |
gptkb:Hubble_Space_Telescope
|