Barnard 33
E459023
Barnard 33, commonly known as the Horsehead Nebula, is a small dark nebula in the constellation Orion whose distinctive horse-head shape is silhouetted against the bright emission nebula IC 434.
All labels observed (3)
| Label | Occurrences |
|---|---|
| IC 434 | 5 |
| Barnard 33 canonical | 3 |
| Barnard 33 (historical designation sometimes confused in literature) | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T4617562 — 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: Barnard 33 Context triple: [Orion Molecular Cloud Complex, contains, Barnard 33]
-
A.
Jewel Box cluster
The Jewel Box cluster is a bright and colorful open star cluster in the constellation Crux, renowned for its striking mix of blue and red stars visible even in small telescopes.
-
B.
Collinder 232
Collinder 232 is an open star cluster located within the Carina Nebula in the constellation Carina.
-
C.
Messier 17
Messier 17, also known as the Omega or Swan Nebula, is a bright star-forming emission nebula located in the constellation Sagittarius.
-
D.
Barnard's Loop
Barnard's Loop is a large, faint emission nebula forming a sweeping arc across the constellation Orion, believed to be the remnant of ancient supernova activity.
-
E.
Trifid Nebula
The Trifid Nebula is a bright, star-forming emission and reflection nebula in the constellation Sagittarius, notable for its three-lobed appearance created by dark dust lanes.
- 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: Barnard 33 Target entity description: Barnard 33, commonly known as the Horsehead Nebula, is a small dark nebula in the constellation Orion whose distinctive horse-head shape is silhouetted against the bright emission nebula IC 434.
-
A.
Jewel Box cluster
The Jewel Box cluster is a bright and colorful open star cluster in the constellation Crux, renowned for its striking mix of blue and red stars visible even in small telescopes.
-
B.
Collinder 232
Collinder 232 is an open star cluster located within the Carina Nebula in the constellation Carina.
-
C.
Messier 17
Messier 17, also known as the Omega or Swan Nebula, is a bright star-forming emission nebula located in the constellation Sagittarius.
-
D.
Barnard's Loop
Barnard's Loop is a large, faint emission nebula forming a sweeping arc across the constellation Orion, believed to be the remnant of ancient supernova activity.
-
E.
Trifid Nebula
The Trifid Nebula is a bright, star-forming emission and reflection nebula in the constellation Sagittarius, notable for its three-lobed appearance created by dark dust lanes.
- F. None of above. chosen
Statements (47)
| Predicate | Object |
|---|---|
| instanceOf |
astronomical object
ⓘ
dark nebula ⓘ molecular cloud ⓘ |
| angularHeightOfHorseHead | about 3.5 arcminutes ⓘ |
| apparentSize | about 8 arcminutes by 6 arcminutes ⓘ |
| associatedWith | star formation ⓘ |
| backgroundEmission | H-alpha emission from IC 434 ⓘ |
| bestSeenFrom | Northern Hemisphere ⓘ |
| bestViewingSeason | winter ⓘ |
| catalog | Barnard Catalogue of Dark Markings in the Sky ⓘ |
| catalogCode | Barnard 33 ⓘ |
| contains |
dense molecular gas
ⓘ
interstellar dust ⓘ |
| declination | −02° 27′ 30″ ⓘ |
| discoveredBy | Williamina Fleming ⓘ |
| discoveryYear | 1888 ⓘ |
| distanceFromEarth |
about 1375 light-years
ⓘ
about 420 parsecs ⓘ |
| dustComposition | silicate and carbonaceous grains ⓘ |
| equatorialCoordinateSystem | J2000 ⓘ |
| featuredIn | many astrophotographs ⓘ |
| gasComposition | primarily molecular hydrogen ⓘ |
| hasColorInImages | dark silhouette against red emission background ⓘ |
| hasCommonName | Horsehead Nebula ⓘ |
| hasFeature |
bright rim on side facing Sigma Orionis
ⓘ
streamers of gas and dust extending from the head region ⓘ |
| illuminatedBy | Sigma Orionis ⓘ |
| influencedBy | radiation from nearby massive stars ⓘ |
| locatedInConstellation | Orion ⓘ |
| locatedInRegion | Orion Molecular Cloud Complex ⓘ |
| mass | several solar masses ⓘ |
| namedBy | Edward Emerson Barnard ⓘ |
| near |
Alnitak
ⓘ
Flame Nebula ⓘ |
| nebulaType | absorption nebula ⓘ |
| observedBy |
Hubble Space Telescope
ⓘ
Subaru Telescope ⓘ Very Large Telescope ⓘ |
| partOf | Orion Belt region ⓘ |
| projectedOn |
IC 434
ⓘ
linked to:
Barnard 33
|
| requires |
dark skies for visual observation
ⓘ
moderate to large telescope for visual observation ⓘ |
| rightAscension | 05h 40m 59s ⓘ |
| shape | horse-head silhouette ⓘ |
| silhouettedAgainst |
IC 434
ⓘ
linked to:
Barnard 33
|
| visibleIn |
infrared wavelengths
ⓘ
optical wavelengths ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: Barnard 33 Description of subject: Barnard 33, commonly known as the Horsehead Nebula, is a small dark nebula in the constellation Orion whose distinctive horse-head shape is silhouetted against the bright emission nebula IC 434.
Referenced by (9)
Full triples — surface form annotated when it differs from this entity's canonical label.
linked to: Barnard 33
subject linked to:
Orion constellation
linked to: Barnard 33
linked to: Barnard 33
linked to: Barnard 33
linked to: Barnard 33