Polaris

E572584

Polaris is the brightest star in the constellation Ursa Minor and the current North Star, lying nearly in line with Earth's rotational axis and serving as a key reference point for navigation in the Northern Hemisphere.

All labels observed (4)

Label Occurrences
Polaris canonical 6
Polaris Ab 2
Polaris B 2

How this entity was disambiguated

Statements (50)

Predicate Object
instanceOf Cepheid variable star
North Star
star
age_millionYears about 70
alsoKnownAs Alpha Ursae Minoris
Alruccabah
α Ursae Minoris
linked to: Alpha Ursae Minoris
angularSeparationFromNorthCelestialPole_degrees less than 1
apparentMagnitude 1.98
colorIndexB−V 0.60
companionStar Polaris Ab
linked to: Polaris

Polaris B
linked to: Polaris
constellation Ursa Minor
declination +89° 15′ 50.8″
distanceFromEarth_ly about 433
distanceFromEarth_pc about 133
eclipticLatitude_degrees about +66
effectiveTemperature_K about 6015
equatorialCoordinatesEpoch J2000.0
galacticPopulation Population I
hasRole pole star
hemisphereVisibility Northern Hemisphere
isBrightestStarOf Ursa Minor
isCircumpolarFrom most mid‑northern latitudes
isNorthStarSince late Middle Ages
locatedIn Milky Way
Ursa Minor constellation region
linked to: Ursa Minor
luminosity_solarLuminosities about 1260
mass_solarMasses about 5.4
metallicity_FeH about +0.07
nearCelestialPole true
orbitalPeriod_PolarisA-Ab_years about 29.6
orbitalPeriod_PolarisA-B_years about 26,000
parallax_mas 7.54
primaryComponent Polaris A
linked to: Polaris
pulsationAmplitude_magnitudes about 0.03
pulsationPeriod_days about 3.97
radialVelocity_kmPerSec −17
radius_solarRadii about 37.5
reasonForNorthStarStatus alignment with Earth rotational axis
rightAscension 02h 31m 49.09s
spectralClass F7Ib
systemComponents Polaris A
Polaris Ab
linked to: Polaris

Polaris B
linked to: Polaris
usedFor celestial navigation
finding geographic north
measuring latitude in Northern Hemisphere
variableType Classical Cepheid
willNotRemainNorthStar true

How these facts were elicited

Referenced by (11)

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

The North Star namedAfter Polaris
Ursa Minor containsStar Polaris
Polaris systemComponents Polaris Ab
linked to: Polaris
Polaris systemComponents Polaris B
linked to: Polaris
Polaris primaryComponent Polaris A
linked to: Polaris
Polaris companionStar Polaris Ab
linked to: Polaris
Polaris companionStar Polaris B
linked to: Polaris
Northern Dipper usedToLocate Polaris
North associatedStar Polaris