Population II

E484154

Population II refers to an older, metal-poor class of stars typically found in globular clusters and the galactic halo, formed early in the history of the universe.

All labels observed (1)

Label Occurrences
Population II canonical 11

How this entity was disambiguated

Statements (49)

Predicate Object
instanceOf astrophysical concept ⓘ
stellar population ⓘ
alsoKnownAs Population II stars ⓘ
characteristicAge old stars ⓘ
chemicalAbundancePattern enhanced alpha-elements relative to iron ⓘ
classificationSystem Baade stellar population classification ⓘ
color generally redder than young massive stars ⓘ
contrastWith Population I ⓘ
Population III ⓘ
discoveredBy Walter Baade ⓘ
discoveryContext resolution of stellar populations in Andromeda ⓘ
discoveryEpoch 1940s ⓘ
formationEpoch early universe ⓘ
formedAfter Population III stars ⓘ
formedFrom gas enriched by first generations of stars ⓘ
foundIn bulge of galaxies ⓘ
dwarf spheroidal galaxies ⓘ
galactic halo ⓘ
globular clusters ⓘ
old stellar halos of galaxies ⓘ
heliumContent lower than in younger populations on average ⓘ
hostOf blue horizontal branch stars ⓘ
many RR Lyrae variable stars ⓘ
importance constrains early star formation history ⓘ
kinematics eccentric orbits ⓘ
high-velocity orbits ⓘ
often highly inclined to galactic disk ⓘ
massRange predominantly low-mass long-lived stars ⓘ
metallicity metal-poor ⓘ
metallicityRelativeToSun lower than solar ⓘ
observationalSignature dominance in globular cluster color-magnitude diagrams ⓘ
weak metal absorption lines in spectra ⓘ
relativeAgeToPopulationI older ⓘ
relativeMetallicityToPopulationI lower ⓘ
roleInCosmology tracers of early galaxy formation ⓘ
roleInDistanceScale includes RR Lyrae variables as standard candles ⓘ
roleInGalacticAstronomy used to study galactic halo structure ⓘ
spatialDistribution spheroidal ⓘ
starFormationActivity no ongoing star formation ⓘ
typicalAgeRange ≈ 10–13 billion years ⓘ
typicalEnvironment low gas density regions ⓘ
typicalLocationInMilkyWay Milky Way globular clusters ⓘ
Milky Way halo ⓘ
typicalMetallicityRange [Fe/H] ≈ −1 to −3 ⓘ
typicalStellarTypes horizontal branch stars ⓘ
low-mass main-sequence stars ⓘ
red giants ⓘ
usedToInfer age of the Milky Way ⓘ
chemical evolution of galaxies ⓘ

How these facts were elicited

Referenced by (11)

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

Messier 28 → stellarPopulation → Population II ⓘ
Messier 30 → stellarPopulation → Population II ⓘ
Population I → youngerThan → Population II ⓘ
Population I → metalRicherThan → Population II ⓘ
Messier 10 → hasStellarPopulation → Population II ⓘ
GCl 99 → galacticPopulation → Population II ⓘ
M75 → stellarPopulation → Population II ⓘ
NGC 5286 → stellarPopulation → Population II ⓘ
NGC 6712 → stellarPopulation → Population II ⓘ
M30 → galacticPopulation → Population II ⓘ
Messier 92 → stellarPopulation → Population II ⓘ