HD 39801
E557730
Milky Way star
bright giant star
cool supergiant
evolved massive star
red supergiant star
semiregular variable star
HD 39801 is the bright red supergiant star Betelgeuse, one of the most prominent stars in the constellation Orion and among the largest visible to the naked eye.
All labels observed (1)
| Label | Occurrences |
|---|---|
| HD 39801 canonical | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T5958657 — 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: HD 39801 Context triple: [Betelgeuse, catalogIdentifier, HD 39801]
-
A.
HD 23180
HD 23180 is a hot, massive early-type star located in the Perseus constellation and is notable as a prominent member of the Perseus OB2 stellar association.
-
B.
HD 24398
HD 24398, also known as ζ Persei, is a bright blue supergiant star in the constellation Perseus and a prominent member of the Perseus OB2 stellar association.
-
C.
HD 29139
HD 29139 is the bright orange giant star Aldebaran, the prominent "eye" of the constellation Taurus and one of the brightest stars in the night sky.
-
D.
HD 23480
HD 23480 is a bright B-type main-sequence star in the constellation Taurus, visible to the naked eye and cataloged under multiple stellar designations including 23 Tauri.
-
E.
HD 4308
HD 4308 is a nearby Sun-like star in the southern constellation Tucana, known for hosting at least one detected exoplanet.
- 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: HD 39801 Target entity description: HD 39801 is the bright red supergiant star Betelgeuse, one of the most prominent stars in the constellation Orion and among the largest visible to the naked eye.
-
A.
HD 23180
HD 23180 is a hot, massive early-type star located in the Perseus constellation and is notable as a prominent member of the Perseus OB2 stellar association.
-
B.
HD 24398
HD 24398, also known as ζ Persei, is a bright blue supergiant star in the constellation Perseus and a prominent member of the Perseus OB2 stellar association.
-
C.
HD 29139
HD 29139 is the bright orange giant star Aldebaran, the prominent "eye" of the constellation Taurus and one of the brightest stars in the night sky.
-
D.
HD 23480
HD 23480 is a bright B-type main-sequence star in the constellation Taurus, visible to the naked eye and cataloged under multiple stellar designations including 23 Tauri.
-
E.
HD 4308
HD 4308 is a nearby Sun-like star in the southern constellation Tucana, known for hosting at least one detected exoplanet.
- F. None of above. chosen
Statements (50)
| Predicate | Object |
|---|---|
| instanceOf |
Milky Way star
ⓘ
bright giant star ⓘ cool supergiant ⓘ evolved massive star ⓘ red supergiant star ⓘ semiregular variable star ⓘ |
| absoluteMagnitudeV | about −5.5 ⓘ |
| age_millionYears | about 8 to 10 ⓘ |
| alsoKnownAs |
Alpha Orionis
NERFINISHED
ⓘ
Betelgeuse NERFINISHED ⓘ |
| angularDiameter_mas | about 40 to 50 milliarcseconds ⓘ |
| apparentMagnitudeV | about 0.0 to +1.6 ⓘ |
| averageApparentMagnitudeV | about +0.5 ⓘ |
| bayerDesignation | α Orionis NERFINISHED ⓘ |
| catalogNumber |
BD+07 1055
NERFINISHED
ⓘ
HD 39801 ⓘ HIP 27989 NERFINISHED ⓘ HR 2061 NERFINISHED ⓘ |
| colorIndexBMinusV | +1.85 ⓘ |
| constellation | Orion NERFINISHED ⓘ |
| declination_J2000 | +07° 24′ 25″ ⓘ |
| dimmingCause2019_2020 | combination of dust formation and surface changes ⓘ |
| distanceFromEarth_ly | about 550 to 650 light-years ⓘ |
| distanceFromEarth_pc | about 170 to 200 parsecs ⓘ |
| effectiveTemperature_K | about 3500 ⓘ |
| evolutionaryStage | late-stage red supergiant ⓘ |
| futureEvolution | core-collapse supernova progenitor ⓘ |
| galacticPopulation | thin disk ⓘ |
| hasCircumstellarMaterial | yes ⓘ |
| hasDustShell | yes ⓘ |
| hasMassLoss | yes ⓘ |
| hemisphereVisibility | both hemispheres ⓘ |
| hostGalaxy | Milky Way NERFINISHED ⓘ |
| isOneOfBrightestStars | yes ⓘ |
| locatedIn | Orion OB1 association NERFINISHED ⓘ |
| luminosity_solar | about 100000 ⓘ |
| mass_solar | about 15 to 20 ⓘ |
| massLossRate_solarMassPerYear | of order 10^-6 to 10^-5 ⓘ |
| metallicity_FeH | near solar ⓘ |
| notableEvent | experienced major dimming in 2019–2020 ⓘ |
| parallax_mas | about 5 to 6 milliarcseconds ⓘ |
| properMotionDec_masPerYear | about 10 ⓘ |
| properMotionRA_masPerYear | about 24 ⓘ |
| radialVelocity_kmPerSec | about +20 ⓘ |
| radius_solar | about 700 to 900 ⓘ |
| rankByBrightness | among top 10 brightest night-sky stars ⓘ |
| rightAscension_J2000 | 05h 55m 10.3s ⓘ |
| spectralType | M1–M2 Ia–ab ⓘ |
| variableType | semiregular (SRC) ⓘ |
| visibleToNakedEye | yes ⓘ |
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: HD 39801 Description of subject: HD 39801 is the bright red supergiant star Betelgeuse, one of the most prominent stars in the constellation Orion and among the largest visible to the naked eye.
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.