Medusa Nebula
E536136
Medusa Nebula is a large, faint planetary nebula in the constellation Gemini, known for its filamentary, serpentine structures that inspired its mythological name.
All labels observed (1)
| Label | Occurrences |
|---|---|
| Medusa Nebula canonical | 2 |
How this entity was disambiguated
This entity first appeared as the object of triple T5573250 — 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: Medusa Nebula Context triple: [Gemini, containsDeepSkyObject, Medusa Nebula]
-
A.
Merope Nebula
The Merope Nebula is a bright reflection nebula in the Pleiades star cluster, illuminated by and surrounding the hot blue star Merope in the constellation Taurus.
-
B.
Tarantula Nebula
The Tarantula Nebula is an enormous, extremely active star-forming region in the Large Magellanic Cloud and one of the most luminous nebulae known in the Local Group of galaxies.
-
C.
Pelican Nebula
The Pelican Nebula is a bright emission nebula in the constellation Cygnus, notable for its bird-like shape and active star-forming regions.
-
D.
Heart Nebula
The Heart Nebula is a vast emission nebula in the constellation Cassiopeia, known for its heart-like shape and active star-forming regions.
-
E.
Rosette Nebula
The Rosette Nebula is a large, circular emission nebula and active star-forming region located in the Milky Way, notable for its striking rose-like appearance in astrophotography.
- 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: Medusa Nebula Target entity description: Medusa Nebula is a large, faint planetary nebula in the constellation Gemini, known for its filamentary, serpentine structures that inspired its mythological name.
-
A.
Merope Nebula
The Merope Nebula is a bright reflection nebula in the Pleiades star cluster, illuminated by and surrounding the hot blue star Merope in the constellation Taurus.
-
B.
Tarantula Nebula
The Tarantula Nebula is an enormous, extremely active star-forming region in the Large Magellanic Cloud and one of the most luminous nebulae known in the Local Group of galaxies.
-
C.
Pelican Nebula
The Pelican Nebula is a bright emission nebula in the constellation Cygnus, notable for its bird-like shape and active star-forming regions.
-
D.
Heart Nebula
The Heart Nebula is a vast emission nebula in the constellation Cassiopeia, known for its heart-like shape and active star-forming regions.
-
E.
Rosette Nebula
The Rosette Nebula is a large, circular emission nebula and active star-forming region located in the Milky Way, notable for its striking rose-like appearance in astrophotography.
- F. None of above. chosen
Statements (47)
| Predicate | Object |
|---|---|
| instanceOf |
emission nebula
ⓘ
planetary nebula ⓘ |
| bestObservedIn | late winter ⓘ |
| bestSeenFrom | Northern Hemisphere ⓘ |
| catalog |
Abell catalog of planetary nebulae
ⓘ
linked to:
Abell catalog of rich clusters of galaxies
Perek-Kohoutek catalog of planetary nebulae ⓘ Sharpless catalog of H II regions ⓘ
linked to:
Sharpless catalogue
|
| discoveredBy | George O. Abell ⓘ |
| discoveryYear | 1955 ⓘ |
| formedFrom | ejected outer layers of a dying star ⓘ |
| hasAge | on the order of tens of thousands of years ⓘ |
| hasAlternativeName |
Abell 21
ⓘ
PK 205+14.1 ⓘ Sh2-274 ⓘ |
| hasAngularSize | about 10 arcminutes ⓘ |
| hasApparentMagnitude | ~10.2 ⓘ |
| hasCentralStar | white dwarf ⓘ |
| hasCentralStarSpectralType | hot subdwarf / white dwarf type ⓘ |
| hasColor |
greenish-blue OIII emission
ⓘ
reddish H-alpha emission ⓘ |
| hasDeclination | +13° 15′ ⓘ |
| hasDiscoveryDesignation | Abell 21 ⓘ |
| hasDistanceFromEarth |
about 1500 light-years
ⓘ
about 460 parsecs ⓘ |
| hasFilamentaryStructure | yes ⓘ |
| hasGalacticLatitude | +14° ⓘ |
| hasGalacticLongitude | 205° ⓘ |
| hasIonizedElements |
hydrogen
ⓘ
nitrogen ⓘ oxygen ⓘ |
| hasMorphologicalType | planetary nebula of old age ⓘ |
| hasNotableFeature |
complex filamentary arcs
ⓘ
serpentine structures resembling snakes of Medusa’s hair ⓘ |
| hasPhysicalNature | ionized gas shell ⓘ |
| hasRightAscension | 07h 29m ⓘ |
| hasSerpentineAppearance | yes ⓘ |
| hasShape | irregular, crescent-like form ⓘ |
| isExtendedSource | yes ⓘ |
| isFaintObject | yes ⓘ |
| locatedIn |
Milky Way
ⓘ
Orion Arm of the Milky Way ⓘ
linked to:
Orion Arm
|
| locatedInConstellation | Gemini ⓘ |
| namedAfter |
Medusa from Greek mythology
ⓘ
linked to:
Medusa
|
| requiresForObservation |
dark skies
ⓘ
moderate to large amateur telescope ⓘ |
| visibleIn |
narrowband filters (H-alpha, OIII)
ⓘ
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: Medusa Nebula Description of subject: Medusa Nebula is a large, faint planetary nebula in the constellation Gemini, known for its filamentary, serpentine structures that inspired its mythological name.
Referenced by (2)
Full triples — surface form annotated when it differs from this entity's canonical label.
subject linked to:
constellation Gemini