Polaris triple star system

URI: https://gptkb.org/entity/Polaris_triple_star_system
GPTKB entity
Statements (52)
Predicate Object
gptkbp:instanceOf gptkb:star
gptkbp:age 70 million years
gptkbp:alsoKnownAs gptkb:Alpha_Ursae_Minoris_system
gptkbp:apparentMagnitude 1.98
gptkbp:brightestStar gptkb:Polaris_Aa
gptkbp:catalogueNumber gptkb:HR_424
gptkb:BD+88_8
gptkb:HD_8890
gptkb:HIP_11767
gptkb:SAO_308
gptkbp:component gptkb:Polaris_Aa
Polaris Ab
gptkbp:constellation gptkb:Ursa_Minor
gptkbp:contains gptkb:Polaris_B
gptkb:Polaris_Aa
Polaris Ab
gptkbp:declination +89° 15′ 50.8″
gptkbp:discoveredBy gptkb:William_Herschel
gptkbp:discoveredIn 1780
gptkbp:distanceFromEarth 433 light years
gptkbp:epoch gptkb:J2000
gptkbp:galacticLatitude +26.46°
123.29°
https://www.w3.org/2000/01/rdf-schema#label Polaris triple star system
gptkbp:isNorthStar true
gptkbp:locatedIn gptkb:Ursa_Minor
gptkbp:luminosity 2200 times Sun (Polaris Aa)
gptkbp:mass 5.4 solar masses (Polaris Aa)
1.26 solar masses (Polaris Ab)
1.39 solar masses (Polaris B)
gptkbp:metallicity [Fe/H] = 0.07
gptkbp:notableFor being the current North Star
gptkbp:orbitType 29.6 years (Aa-Ab)
gptkbp:parallax 7.54 mas
gptkbp:properMotionRA -11.74 mas/yr (Dec)
44.22 mas/yr (RA)
gptkbp:radialVelocity -16.6 km/s
gptkbp:rightAscension 02h 31m 49.09s
gptkbp:separates 18.8 AU (Aa-Ab)
2400 AU (Aa-B)
gptkbp:spectralType F3V (Polaris B)
F6V (Polaris Ab)
F7:Ib (Polaris Aa)
gptkbp:surfaceGravity log(g) = 2.2 (Polaris Aa)
log(g) = 4.3 (Polaris B)
gptkbp:temperature 6015 K (Polaris Aa)
6900 K (Polaris B)
gptkbp:tertiaryComponent gptkb:Polaris_B
gptkbp:variableType Cepheid variable (Polaris Aa)
gptkbp:bfsParent gptkb:Nord
gptkb:The_North_Star
gptkbp:bfsLayer 5