redSupergiant Stephenson 2-18
E459136
Stephenson 2-18 is an extremely luminous red supergiant star, considered one of the largest known stars in the Milky Way.
All labels observed (1)
| Label | Occurrences |
|---|---|
| redSupergiant Stephenson 2-18 canonical | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T4619162 — 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: redSupergiant Stephenson 2-18 Context triple: [Scutum, contains, redSupergiant Stephenson 2-18]
-
A.
Baade’s star
Baade’s star is a luminous, variable star in the Andromeda Galaxy notable for its role in Walter Baade’s work refining the cosmic distance scale.
-
B.
Eta Carinae
Eta Carinae is a highly luminous and unstable massive stellar system in the constellation Carina, famous for its 19th-century "Great Eruption" and its surrounding Homunculus Nebula.
-
C.
Cepheid
Cepheid is a molecular diagnostics company known for its rapid, automated PCR-based testing systems used in clinical and research settings.
-
D.
30 Doradus
30 Doradus, also known as the Tarantula Nebula, is a vast and intensely active star-forming region and emission nebula in the Large Magellanic Cloud.
-
E.
Trumpler 16
Trumpler 16 is a massive young star cluster in the Carina Nebula, notable for hosting some of the most luminous and massive known stars, including Eta Carinae.
- 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: redSupergiant Stephenson 2-18 Target entity description: Stephenson 2-18 is an extremely luminous red supergiant star, considered one of the largest known stars in the Milky Way.
-
A.
Baade’s star
Baade’s star is a luminous, variable star in the Andromeda Galaxy notable for its role in Walter Baade’s work refining the cosmic distance scale.
-
B.
Eta Carinae
Eta Carinae is a highly luminous and unstable massive stellar system in the constellation Carina, famous for its 19th-century "Great Eruption" and its surrounding Homunculus Nebula.
-
C.
Cepheid
Cepheid is a molecular diagnostics company known for its rapid, automated PCR-based testing systems used in clinical and research settings.
-
D.
30 Doradus
30 Doradus, also known as the Tarantula Nebula, is a vast and intensely active star-forming region and emission nebula in the Large Magellanic Cloud.
-
E.
Trumpler 16
Trumpler 16 is a massive young star cluster in the Carina Nebula, notable for hosting some of the most luminous and massive known stars, including Eta Carinae.
- F. None of above. chosen
Statements (44)
| Predicate | Object |
|---|---|
| instanceOf |
cool supergiant
ⓘ
luminous supergiant ⓘ red supergiant star ⓘ star ⓘ |
| discoveredBy | Charles Bruce Stephenson ⓘ |
| discoveryMethod | infrared survey ⓘ |
| hasAlternativeName |
RSGC2-18
ⓘ
St2-18 ⓘ Stephenson 2 DFK 49 ⓘ |
| hasApparentMagnitude | very faint in visible light ⓘ |
| hasApproximateDistanceFromEarth |
about 19,000 light-years
ⓘ
about 6 kiloparsecs ⓘ |
| hasApproximateLuminosity | hundreds of thousands of times the luminosity of the Sun ⓘ |
| hasApproximateRadius |
over 2000 times the radius of the Sun
ⓘ
over 9 astronomical units ⓘ |
| hasColor | red ⓘ |
| hasEffectiveTemperature | approximately 3200 K ⓘ |
| hasEstimatedInitialMass | tens of solar masses ⓘ |
| hasEvolutionaryStage | late stage massive star ⓘ |
| hasExtendedStellarAtmosphere | true ⓘ |
| hasGalacticEnvironment | highly reddened region ⓘ |
| hasGalacticLocation | inner Milky Way disk ⓘ |
| hasHighInfraredBrightness | true ⓘ |
| hasHighMassLossRate | true ⓘ |
| hasLuminosityClass | Ia ⓘ |
| hasOuterLayers | cool extended envelope ⓘ |
| hasResearchInterest |
late stages of massive stars
ⓘ
mass loss in red supergiants ⓘ massive star evolution ⓘ |
| hasSpectralClass | M6 ⓘ |
| hasSpectralType | M-type ⓘ |
| hasStellarPopulation | Population I ⓘ |
| hasStellarWind | dense slow stellar wind ⓘ |
| hasVariability | suspected semiregular variability ⓘ |
| isAmong |
largest known stars
ⓘ
most luminous red supergiants ⓘ |
| isEmbeddedIn |
rich red supergiant cluster Stephenson 2
ⓘ
linked to:
openCluster Stephenson 2
|
| isObscuredBy | interstellar dust ⓘ |
| isUsedAs |
example of extreme red supergiant
ⓘ
example of extreme stellar radius ⓘ |
| locatedIn |
Milky Way
ⓘ
constellation Scutum ⓘ
linked to:
Scutum constellation
|
| memberOf |
open cluster Stephenson 2
ⓘ
linked to:
openCluster Stephenson 2
|
| willEndAs | core-collapse supernova ⓘ |
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: redSupergiant Stephenson 2-18 Description of subject: Stephenson 2-18 is an extremely luminous red supergiant star, considered one of the largest known stars in the Milky Way.
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.