HR 1903

E545061

HR 1903 is the Bright Star Catalogue designation for Alnilam, the luminous blue supergiant star forming the central point of Orion’s Belt.

All labels observed (1)

Label Occurrences
HR 1903 canonical 2

How this entity was disambiguated

Statements (46)

Predicate Object
instanceOf Bright Star Catalogue object
blue supergiant
star
alsoKnownAs Alnilam
Epsilon Orionis
apparentMagnitudeV 1.69
belongsTo Milky Way Galaxy
linked to: Milky Way

Orion OB1 association
bestViewingSeason northern winter
catalogDesignation BD−01°969
HD 37128
HIP 26311
HR 1903
SAO 132444
colorIndex blue
constellation Orion
declination −01° 12′
distanceFromEarth_ly about 2000
distanceFromEarth_pc about 600
dominantEnergyOutput ultraviolet radiation
effectiveTemperature_K about 27500
equatorialCoordinateSystem J2000
evolutionaryStage supergiant
galacticPopulation Population I
hasProperName Alnilam
hasRadialVelocity about +27 km/s
hasRotationalVelocity about 40 km/s
hemisphereVisibility both northern and southern hemispheres
influences surrounding interstellar medium in Orion
isMassiveStar true
isOneOf three main stars of Orion’s Belt
isPartOf Orion’s Belt
linked to: Orion Belt region
isSingleStar likely
isVisibleToNakedEye true
luminosityComparedToSun about 375000
massComparedToSun about 30
metallicityComparedToSun slightly subsolar
nameEtymology from Arabic meaning “string of pearls” or “sapphire”
neighboringBeltStar Alnitak
Mintaka
positionInAsterism central star of Orion’s Belt
radiusComparedToSun about 32
rightAscension 05h 36m
spectralType B0Ia
variableStarType Alpha Cygni-type candidate
willEndAs core-collapse supernova

How these facts were elicited

Referenced by (2)

Full triples — surface form annotated when it differs from this entity's canonical label.

Alnilam catalogIdentifier HR 1903
HR 1903 catalogDesignation HR 1903