Cepheid variables
E581535
Cepheid variables are pulsating stars whose regular brightness variations make them crucial standard candles for measuring cosmic distances and mapping galactic structure.
Statements (51)
| Predicate | Object |
|---|---|
| instanceOf |
class of variable stars
ⓘ
standard candles ⓘ |
| distinguishedBy |
correlation between pulsation period and intrinsic luminosity
ⓘ
regular, predictable light curves ⓘ |
| exhibits |
periodic brightness variations
ⓘ
radial pulsations ⓘ |
| hasAlternativeName |
Cepheid variable stars
ⓘ
Cepheids NERFINISHED ⓘ |
| hasCauseOfPulsation |
kappa mechanism
ⓘ
opacity changes in partial ionization zones ⓘ |
| hasCauseOfVariability | pulsation of stellar envelope ⓘ |
| hasDiscovery | period–luminosity relation discovered by Henrietta Swan Leavitt ⓘ |
| hasKeyProperty |
period–color relation
ⓘ
period–luminosity relation ⓘ period–radius relation ⓘ |
| hasLightCurveShape | sawtooth-like in many cases ⓘ |
| hasLuminosityClass | I (supergiant) ⓘ |
| hasPhaseRelation | maximum brightness occurs near minimum radius ⓘ |
| hasSpectralTypeRange |
F-type supergiants
ⓘ
G-type supergiants ⓘ |
| hasSubClass |
Anomalous Cepheids
NERFINISHED
ⓘ
Classical Cepheids NERFINISHED ⓘ Type II Cepheids NERFINISHED ⓘ |
| hasTypicalAbsoluteMagnitudeRange | about −2 to −6 in V band ⓘ |
| hasTypicalAgeRange | tens to hundreds of millions of years (Classical Cepheids) ⓘ |
| hasTypicalAmplitudeRange | about 0.1 to 2 magnitudes in visible light ⓘ |
| hasTypicalMassRange | about 3 to 15 solar masses (Classical Cepheids) ⓘ |
| hasTypicalPeriodRange | 1 to 100 days ⓘ |
| hasTypicalTemperatureVariation | several hundred to a few thousand Kelvin over a cycle ⓘ |
| importantFor | establishing the first rung of the cosmic distance ladder ⓘ |
| modeledBy | stellar pulsation theory ⓘ |
| namedAfter | Delta Cephei NERFINISHED ⓘ |
| observedIn |
Large Magellanic Cloud
NERFINISHED
ⓘ
Milky Way NERFINISHED ⓘ Small Magellanic Cloud NERFINISHED ⓘ many nearby galaxies ⓘ |
| periodLuminosityRelationPublishedIn | 1912 ⓘ |
| requiresForAccurateUse |
corrections for interstellar extinction
ⓘ
metallicity corrections ⓘ |
| traces |
older stellar populations (Type II Cepheids)
ⓘ
young stellar populations (Classical Cepheids) ⓘ |
| typicallyFoundIn |
irregular galaxies
ⓘ
spiral galaxies ⓘ |
| usedAs | primary distance indicators ⓘ |
| usedFor |
calibrating Type Ia supernova luminosities
ⓘ
calibrating the extragalactic distance scale ⓘ determining the Hubble constant ⓘ mapping galactic structure ⓘ measuring distances to nearby galaxies ⓘ measuring distances within the Milky Way ⓘ tracing spiral arms in disk galaxies ⓘ |
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.