|
gptkbp:instanceOf
|
variable star
|
|
gptkbp:age
|
>10 billion years
|
|
gptkbp:color
|
B-V ≈ 0.2–0.5
|
|
gptkbp:commonIn
|
old stellar populations
|
|
gptkbp:coreProcess
|
helium burning
|
|
gptkbp:discoveredBy
|
gptkb:Williamina_Fleming
1899
|
|
gptkbp:distanceCalibration
|
standard candle
|
|
gptkbp:distanceRangeObserved
|
up to 100 kpc
|
|
gptkbp:evolutionaryStage
|
horizontal branch
|
|
gptkbp:foundIn
|
gptkb:galaxy
globular clusters
|
|
gptkbp:galacticDistribution
|
spherical halo
|
|
gptkbp:heliumFusion
|
yes
|
|
gptkbp:hostedBy
|
gptkb:Milky_Way
gptkb:Andromeda_Galaxy
dwarf spheroidal galaxies
|
|
https://www.w3.org/2000/01/rdf-schema#label
|
RR Lyrae stars
|
|
gptkbp:lightCurveShape
|
sawtooth
|
|
gptkbp:luminosity
|
gptkb:giant
|
|
gptkbp:mass
|
~0.6 to 0.8 solar masses
|
|
gptkbp:meanApparentMagnitude
|
varies
|
|
gptkbp:metallicity
|
low
|
|
gptkbp:metallicityRange
|
[Fe/H] ≈ -2.5 to -0.5
|
|
gptkbp:namedAfter
|
gptkb:RR_Lyrae
|
|
gptkbp:notableExample
|
gptkb:RR_Lyrae
|
|
gptkbp:periodLuminosityRelation
|
weak
|
|
gptkbp:periodRange
|
0.2 to 1 day
|
|
gptkbp:population
|
gptkb:Population_II
|
|
gptkbp:pulsationMode
|
fundamental
double mode
first overtone
|
|
gptkbp:spectralType
|
A
F
|
|
gptkbp:stellarPopulation
|
old, metal-poor stars
|
|
gptkbp:subspecies
|
gptkb:RRab
gptkb:RRc
gptkb:RRd
|
|
gptkbp:temperature
|
6000–7600 K
|
|
gptkbp:typicalAbsoluteMagnitude
|
+0.75
|
|
gptkbp:usedFor
|
distance indicators
calibrating cosmic distance scale
|
|
gptkbp:usedIn
|
mapping Milky Way structure
measuring galactic distances
|
|
gptkbp:variabilityAmplitude
|
0.3–2 magnitudes
|
|
gptkbp:variabilityCause
|
radial pulsation
|
|
gptkbp:variableType
|
pulsating variable
|
|
gptkbp:bfsParent
|
gptkb:Population_II
gptkb:Population_II_stars
gptkb:Sagittarius_Stream
|
|
gptkbp:bfsLayer
|
6
|