Zeta Orionis
E540362
O-type supergiant
massive star
multiple star system
proper name of a star system
star in Orion's Belt
Zeta Orionis, traditionally known as Alnitak, is a massive, hot blue multiple star system forming the easternmost star of Orion’s Belt.
All labels observed (6)
| Label | Occurrences |
|---|---|
| Zeta Orionis canonical | 6 |
| ζ Orionis | 5 |
| Zeta Ori | 1 |
| Zeta Orionis A | 1 |
| Zeta Orionis B | 1 |
| Zeta Orionis C | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T5723587 — 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: Zeta Orionis Context triple: [Alnitak, hasBayerDesignation, Zeta Orionis]
-
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.
Zeta Sagittarii
Zeta Sagittarii is a bright multiple star system in the constellation Sagittarius, forming part of the asterism known as the Teapot.
-
C.
Epsilon Canis Majoris
Epsilon Canis Majoris, also known as Adhara, is a bright blue-white giant star and one of the most luminous stars visible from Earth, located in the constellation Canis Major.
-
D.
Rigel
Rigel is a luminous blue supergiant star and one of the brightest stars in the night sky, prominently marking the foot of the constellation Orion.
-
E.
Aludra
Aludra is a bright blue supergiant star in the constellation Canis Major, known for its high luminosity and relatively short remaining lifespan.
- 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: Zeta Orionis Target entity description: Zeta Orionis, traditionally known as Alnitak, is a massive, hot blue multiple star system forming the easternmost star of Orion’s Belt.
-
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.
Zeta Sagittarii
Zeta Sagittarii is a bright multiple star system in the constellation Sagittarius, forming part of the asterism known as the Teapot.
-
C.
Epsilon Canis Majoris
Epsilon Canis Majoris, also known as Adhara, is a bright blue-white giant star and one of the most luminous stars visible from Earth, located in the constellation Canis Major.
-
D.
Rigel
Rigel is a luminous blue supergiant star and one of the brightest stars in the night sky, prominently marking the foot of the constellation Orion.
-
E.
Aludra
Aludra is a bright blue supergiant star in the constellation Canis Major, known for its high luminosity and relatively short remaining lifespan.
- F. None of above. chosen
Statements (42)
| Predicate | Object |
|---|---|
| instanceOf |
O-type supergiant
ⓘ
massive star ⓘ multiple star system ⓘ proper name of a star system ⓘ star in Orion's Belt ⓘ |
| alsoKnownAs |
Alnitak
ⓘ
Zeta Ori ⓘ
linked to:
Zeta Orionis
ζ Orionis ⓘ
linked to:
Zeta Orionis
|
| apparentMagnitudeV | 1.72 ⓘ |
| bayerDesignation |
ζ Orionis
ⓘ
linked to:
Zeta Orionis
|
| bestSeenIn | northern winter ⓘ |
| color | blue ⓘ |
| componentOfAsterism |
Orion's Belt
ⓘ
linked to:
Orion Belt region
|
| constellation | Orion ⓘ |
| culturalSignificance | important star in many mythologies associated with Orion ⓘ |
| declination_J2000 | −01° 56′ 34″ ⓘ |
| distanceFromEarth_ly | about 1260 ⓘ |
| distanceFromEarth_pc | about 387 ⓘ |
| effectiveTemperature_K | about 30000 ⓘ |
| evolutionaryStage | supergiant phase ⓘ |
| flamsteedDesignation | 50 Orionis ⓘ |
| galacticPopulation | thin disk ⓘ |
| hasComponent |
Zeta Orionis A
ⓘ
linked to:
Zeta Orionis
Zeta Orionis B ⓘ
linked to:
Zeta Orionis
Zeta Orionis C ⓘ
linked to:
Zeta Orionis
|
| hasProperName | Alnitak ⓘ |
| locatedIn | Milky Way ⓘ |
| luminosityComparedToSun | hundreds of thousands times solar luminosity ⓘ |
| massComparedToSun | significantly more massive than the Sun ⓘ |
| notableFor |
being one of the brightest O-type stars visible to the naked eye
ⓘ
forming the eastern end of Orion's Belt ⓘ |
| observedIn |
X-ray wavelengths
ⓘ
optical wavelengths ⓘ ultraviolet wavelengths ⓘ |
| partOf |
Orion OB1 association
ⓘ
linked to:
Orion OB association
|
| positionInOrionsBelt | easternmost star ⓘ |
| radialVelocity_km_s | about +18 ⓘ |
| refersTo | Zeta Orionis ⓘ |
| rightAscension_J2000 | 05h 40m 45.5s ⓘ |
| spectralType | O9.5 Iab ⓘ |
| variableStarType | slight variability reported ⓘ |
| visibleFrom | both hemispheres ⓘ |
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: Zeta Orionis Description of subject: Zeta Orionis, traditionally known as Alnitak, is a massive, hot blue multiple star system forming the easternmost star of Orion’s Belt.
Referenced by (15)
Full triples — surface form annotated when it differs from this entity's canonical label.
linked to: Zeta Orionis
linked to: Zeta Orionis
linked to: Zeta Orionis
linked to: Zeta Orionis
linked to: Zeta Orionis
linked to: Zeta Orionis
subject linked to:
Zeta Orionis
linked to: Zeta Orionis
linked to: Zeta Orionis
linked to: Zeta Orionis