Plaskett’s Star
E545073
Plaskett’s Star is a massive, highly luminous spectroscopic binary system composed of two very hot O-type stars, notable as one of the most massive known binary star systems in the Milky Way.
All labels observed (3)
| Label | Occurrences |
|---|---|
| Plaskett’s Star canonical | 1 |
| Plaskett’s Star A | 1 |
| Plaskett’s Star B | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T5775499 — 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: Plaskett’s Star Context triple: [Monoceros, contains, Plaskett’s Star]
-
A.
Zeta Tucanae
Zeta Tucanae is a main-sequence F-type star located in the southern constellation Tucana, visible to the naked eye from dark-sky locations.
-
B.
Sigma Sagittarii
Sigma Sagittarii is a bright blue-white giant star in the constellation Sagittarius, marking one of the prominent points of the Teapot asterism.
-
C.
Alpha Centauri
Alpha Centauri is the closest star system to the Solar System, consisting of a triple-star arrangement that includes the Sun-like stars Alpha Centauri A and B and the red dwarf Proxima Centauri.
-
D.
Zeta Sagittarii
Zeta Sagittarii is a bright multiple star system in the constellation Sagittarius, forming part of the asterism known as the Teapot.
-
E.
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.
- 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: Plaskett’s Star Target entity description: Plaskett’s Star is a massive, highly luminous spectroscopic binary system composed of two very hot O-type stars, notable as one of the most massive known binary star systems in the Milky Way.
-
A.
Zeta Tucanae
Zeta Tucanae is a main-sequence F-type star located in the southern constellation Tucana, visible to the naked eye from dark-sky locations.
-
B.
Sigma Sagittarii
Sigma Sagittarii is a bright blue-white giant star in the constellation Sagittarius, marking one of the prominent points of the Teapot asterism.
-
C.
Alpha Centauri
Alpha Centauri is the closest star system to the Solar System, consisting of a triple-star arrangement that includes the Sun-like stars Alpha Centauri A and B and the red dwarf Proxima Centauri.
-
D.
Zeta Sagittarii
Zeta Sagittarii is a bright multiple star system in the constellation Sagittarius, forming part of the asterism known as the Teapot.
-
E.
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.
- F. None of above. chosen
Statements (45)
| Predicate | Object |
|---|---|
| instanceOf |
O-type star binary
ⓘ
massive O-type star ⓘ massive binary star system ⓘ spectroscopic binary star system ⓘ |
| belongsTo |
Monoceros OB association (approximate large-scale grouping)
ⓘ
linked to:
Monoceros OB2 association
|
| hasAlternativeName |
BD+06 1309
ⓘ
HD 47129 ⓘ HIP 31625 ⓘ HR 2422 ⓘ SAO 114010 ⓘ V640 Monocerotis ⓘ
linked to:
S Monocerotis
|
| hasApparentMagnitudeV | 6.06 ⓘ |
| hasColorIndexBminusV | approximately 0.0 to +0.1 (heavily reddened O-type) ⓘ |
| hasComponent |
Plaskett’s Star A
ⓘ
linked to:
Plaskett’s Star
Plaskett’s Star B ⓘ
linked to:
Plaskett’s Star
|
| hasDeclination | +06° 08′ (approximate) ⓘ |
| hasDiscoverer | John Stanley Plaskett ⓘ |
| hasDiscoveryDate | early 20th century ⓘ |
| hasDiscoveryMethod | spectroscopic observation ⓘ |
| hasDistanceFromEarth |
about 1.6 kiloparsecs
ⓘ
about 5200 light-years ⓘ |
| hasEffectiveTemperature | over 30,000 K (each component, order of magnitude) ⓘ |
| hasEvolutionaryStatus | massive, evolved O-type stars ⓘ |
| hasGalacticPopulation | Population I ⓘ |
| hasLuminosity | several hundred thousand times solar luminosity (order of magnitude) ⓘ |
| hasMass |
about 50 solar masses (order of magnitude)
ⓘ
total system mass over 100 solar masses (approximate) ⓘ |
| hasOrbitalEccentricity | low (nearly circular orbit) ⓘ |
| hasOrbitalPeriod | about 14.4 days ⓘ |
| hasPhotometricVariabilityCause | ellipsoidal variations and wind effects ⓘ |
| hasPotentialFuture | likely core-collapse supernovae of components ⓘ |
| hasRadialVelocity | approximately +30 km/s (order of magnitude, variable) ⓘ |
| hasRightAscension | 06h 37m (approximate) ⓘ |
| hasSpectralType |
O7.5 III (secondary component, approximate)
ⓘ
O8 I (primary component, approximate) ⓘ |
| hasSpectroscopicBinaryType | double-lined spectroscopic binary ⓘ |
| hasStellarWind | strong ⓘ |
| hasStellarWindInteraction | colliding winds between components ⓘ |
| hasVariableStarDesignation | V640 Mon ⓘ |
| hasXRayEmission | yes, from colliding winds ⓘ |
| isAmong | most massive known binary star systems in the Milky Way ⓘ |
| isVariableStar | true ⓘ |
| locatedIn |
Milky Way
ⓘ
constellation Monoceros ⓘ
linked to:
Monoceros
|
| namedAfter | John Stanley Plaskett ⓘ |
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: Plaskett’s Star Description of subject: Plaskett’s Star is a massive, highly luminous spectroscopic binary system composed of two very hot O-type stars, notable as one of the most massive known binary star systems in the Milky Way.
Referenced by (3)
Full triples — surface form annotated when it differs from this entity's canonical label.
linked to: Plaskett’s Star
linked to: Plaskett’s Star