RR Lyrae variable stars
E492359
RR Lyrae variable stars are old, low-mass pulsating stars used as standard candles to measure distances within the Milky Way and nearby galaxies.
Observed surface forms (2)
| Surface form | Occurrences |
|---|---|
| RR Lyrae variable star | 0 |
| RR Lyrae variables | 2 |
Statements (49)
| Predicate | Object |
|---|---|
| instanceOf |
Population II star
ⓘ
horizontal branch star ⓘ pulsating variable star ⓘ standard candle ⓘ |
| calibratedBy |
Gaia mission data
ⓘ
parallax measurements ⓘ |
| discovered | early 20th century ⓘ |
| distanceScaleUse |
Local Group distance scale
ⓘ
Milky Way distance scale ⓘ |
| evolutionaryStage | core helium-burning phase ⓘ |
| foundIn |
Milky Way
NERFINISHED
ⓘ
galactic halo ⓘ globular cluster ⓘ nearby galaxy ⓘ |
| hostGalaxyComponent |
dwarf spheroidal galaxy
ⓘ
thick disk ⓘ |
| lightCurveShapeRRab | asymmetric sawtooth ⓘ |
| lightCurveShapeRRc | more sinusoidal ⓘ |
| locatedIn | instability strip ⓘ |
| metallicity | metal-poor ⓘ |
| namedAfter | RR Lyrae NERFINISHED ⓘ |
| observationalBand |
infrared
ⓘ
optical ⓘ |
| periodLuminosityRelation |
present but weaker in optical bands
ⓘ
tight in infrared bands ⓘ |
| RRabCharacteristics | fundamental-mode pulsators ⓘ |
| RRcCharacteristics | first-overtone pulsators ⓘ |
| RRdCharacteristics | double-mode pulsators ⓘ |
| spectralTypeRange | A to F ⓘ |
| subclass |
RRab
ⓘ
RRc ⓘ RRd ⓘ |
| tracesComponent |
old bulge population
ⓘ
stellar halo ⓘ |
| typicalAbsoluteMagnitudeV | around +0.6 ⓘ |
| typicalAge | old ⓘ |
| typicalAmplitudeRangeV | 0.3 to 2 magnitudes ⓘ |
| typicalEffectiveTemperatureRange | about 6000 to 7500 K ⓘ |
| typicalLocationInCluster | horizontal branch of color-magnitude diagram ⓘ |
| typicalLuminosity | about 40 to 50 times solar luminosity ⓘ |
| typicalMass | about 0.6 to 0.8 solar masses ⓘ |
| typicalMetallicityRange | [Fe/H] from about −2.5 to −0.5 ⓘ |
| typicalPeriodRange | 0.2 to 1 day ⓘ |
| typicalPopulation | Population II ⓘ |
| usedFor |
Galactic structure studies
ⓘ
distance measurement ⓘ tracing old stellar populations ⓘ |
| variabilityCause | radial pulsation ⓘ |
| variabilityMechanism | kappa mechanism ⓘ |
Referenced by (3)
Full triples — surface form annotated when it differs from this entity's canonical label.
this entity surface form:
RR Lyrae variables
this entity surface form:
RR Lyrae variables