Alpha Orionis

E557727

Alpha Orionis is the Bayer designation for Betelgeuse, a prominent red supergiant star in the constellation Orion known for its brightness and variability.

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Observed surface forms (1)

Surface form Occurrences
α Orionis 1

Statements (48)

Predicate Object
instanceOf star
alsoKnownAs Betelgeuse NERFINISHED
α Orionis NERFINISHED
exhibitsMassLoss true
formsPartOfAsterism Orion constellation figure
greatDimmingCause combination of dust formation and surface changes
hasAngularDiameter about 0.04 arcseconds
hasApparentMagnitudeV about 0.0 to +1.6
hasAverageApparentMagnitudeV about +0.5
hasBayerDesignation α Orionis NERFINISHED
hasCircumstellarDust true
hasColorIndexBminusV +1.85
hasCulturalSignificance featured in many mythologies and modern media
hasDeclination +07° 24′ 25.4″
hasDistanceFromEarth about 170 parsecs
about 550 light-years
hasEffectiveTemperature about 3500 K
hasEquinox J2000.0
hasEstimatedRemainingLifetime on the order of 10^5 years
hasExtendedAtmosphere true
hasFlamsteedDesignation 58 Orionis NERFINISHED
hasLuminosity about 100,000 times solar luminosity
hasMass about 10–20 solar masses
hasMassLossRate about 1–2 × 10^-6 solar masses per year
hasMetallicityFeH approximately solar
hasParallax about 4.51 mas
hasPrimaryVariabilityPeriod about 400 days
hasProperMotionInDec about 9.56 mas/yr
hasProperMotionInRA about 24.95 mas/yr
hasRadialVelocity about +21 km/s
hasRadius about 700–1000 solar radii
hasRightAscension 05h 55m 10.3053s
hasSecondaryVariabilityPeriod about 2000 days
hasSpectralType M1–M2 Ia–ab
hasStellarWind true
hasSurfaceConvectionCells true
hasVariableType semiregular variable
isBrightestStarInConstellation Orion NERFINISHED
isEvolvedStar true
isExpectedToEndAs core-collapse supernova
isIrregularInShape true
isNorthernHemisphereWinterStar true
isOneOfBrightestStarsInSky true
isRedSupergiantPhase true
isShoulderOfOrion true
isVisibleToNakedEye true
locatedInConstellation Orion NERFINISHED
wasObservedToDimUnusually 2019–2020 great dimming event

Referenced by (2)

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

Betelgeuse BayerDesignation Alpha Orionis
this entity surface form: α Orionis
Betelgeuse variableStarDesignation Alpha Orionis