M21
E1324770
UNEXPLORED
M21 is a young open star cluster in the constellation Sagittarius, notable for its bright, densely packed stars and proximity to the Trifid Nebula.
All labels observed (1)
| Label | Occurrences |
|---|---|
| M21 canonical | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T18443548 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: M21 Context triple: [Messier 21, otherName, M21]
-
A.
M22
M22 is a bright globular star cluster in the constellation Sagittarius, notable for being one of the closest and most easily observed globular clusters from Earth.
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B.
M-21
The M-21 was a specialized variant of the Lockheed A-12 reconnaissance aircraft, modified to carry and launch the D-21 unmanned reconnaissance drone from its back at high altitude and speed.
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C.
M-21
M-21 is a state highway in Michigan that serves as an important east–west transportation route across the central part of the state.
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D.
M24
M24 is a rich star cloud in the constellation Sagittarius, visible as a bright patch of the Milky Way and often observed by amateur astronomers.
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E.
M-2
M-2 is a major motorway designated as route M-2, typically serving as an important high-speed road corridor in its region.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: M21 Target entity description: M21 is a young open star cluster in the constellation Sagittarius, notable for its bright, densely packed stars and proximity to the Trifid Nebula.
-
A.
M22
M22 is a bright globular star cluster in the constellation Sagittarius, notable for being one of the closest and most easily observed globular clusters from Earth.
-
B.
M-21
The M-21 was a specialized variant of the Lockheed A-12 reconnaissance aircraft, modified to carry and launch the D-21 unmanned reconnaissance drone from its back at high altitude and speed.
-
C.
M-21
M-21 is a state highway in Michigan that serves as an important east–west transportation route across the central part of the state.
-
D.
M24
M24 is a rich star cloud in the constellation Sagittarius, visible as a bright patch of the Milky Way and often observed by amateur astronomers.
-
E.
M-2
M-2 is a major motorway designated as route M-2, typically serving as an important high-speed road corridor in its region.
- F. None of above. chosen
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.