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physical object > natural object > celestial body > star > metal-poor star > horizontal branch star > RR Lyrae star
Uphorizontal branch star, periodic variable

RR Lyrae star
(cluster variable, cluster variable)
subjectfact 
RR Lyrae starhas synonym cluster variable2001-09-27 09:30:37.0
has synonym cluster variablehas source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:30:37.0
has definition Periodic variable with period less than one day, and of spectral types A to early F.has source: Jaschek, C., Jaschek, M. 1995 The Behavior of Chemical Elements in Stars, Cambridge University Press, 2001-09-27 09:30:37.0
has definition Type of short-period variable stars. Spectrally classified as A to F giants. They were once called cluster-cepheids.has source: Abbot, D. 1984 Astronomers, Peter Bedrick Books, New York, 2001-09-27 09:30:37.0
has definition A large class of pulsating (amplitude variation about 1 mag) blue giants of anomalous spectral type (A2-F6) with periods of less than 1 day. Their average absolute magnitude is about +0.8. which makes them almost 50 times more luminous than the Sun. They are Population II objects often (but not always) present in globular clusters. RR Lyrae stars are valid distance indicators out to more than 200 kpc.has source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:30:37.0
is a kind of periodic variable2001-09-27 09:30:37.0
is a kind of horizontal branch star2001-09-27 09:30:37.0
horizontal branch starhas color blue to yellow2001-09-27 09:30:26.0
has location on H-R diagram extends shortward from the asymptotic branch at an approximately constant absolute bolometric magnitude of about 0.32001-09-27 09:30:26.0
periodic variablehas period2001-09-27 09:30:34.0
metal-poor starhas metallic line strength weak2001-09-27 09:30:26.0
variablehas name designated with
  1. R, S, T, U, V, W, X, Y, or Z and the genitive of the latin constellation name
  2. RR, RS, RT, RU, RV, RW, RX, RY, or RZ and the genitive of the latin constellation name when the single letter designations are exhausted
  3. AA...AZ, BB...BZ, etc. (omitting J), which ends with QQ...QZ and the genitive of the latin constellation namewhen the RR...RZ designations are exhausted
  4. V 335, V 336, etc., when the double letter designations are exhausted
2001-09-27 09:30:34.0
has observational problem some difficulty in distinguishing between various kinds2001-09-27 09:30:34.0
has observable variation time scale within a period of decadeshas URL: http://www.aavso.org, 2001-09-27 09:30:34.0
has light curve2001-09-27 09:30:34.0
has optical brightness variation 0.2 magnitudes or greater2001-09-27 09:30:34.0
has amplitude2001-09-27 09:30:34.0
starhas star surface temperature2001-09-27 09:30:25.0
has spectral type2001-09-27 09:30:25.0
has V magnitude2001-09-27 09:30:25.0
has B magnitude2001-09-27 09:30:25.0
has U magnitude2001-09-27 09:30:25.0
has position on celestial sphere from the point of view of Earth2001-09-27 09:30:25.0
has parallax from the point of view of Earth's orbit2001-09-27 09:30:25.0
has proper motion2001-09-27 09:30:24.0
has radiation at surface which is diffused out from the hotter core2001-09-27 09:30:24.0
has energy source gravitational contraction and or fusion2001-09-27 09:30:24.0
has energy production which takes place primarily within the core2001-09-27 09:30:24.0
has surface density which depends on luminosity class2001-09-27 09:30:24.0
has surface temperature greater than 1000 Kelvin2001-09-27 09:30:24.0
has apparent magnitude2001-09-27 09:30:25.0
has absolute magnitude2001-09-27 09:30:25.0
has age2001-09-27 09:30:25.0
has catalog star catalog2001-09-27 09:30:25.0
has material hydrogen, helium2001-09-27 09:30:24.0
has velocity determined from proper motion and radial velocity2001-09-27 09:30:25.0
has mass greater than 0.08 the sun's mass2001-09-27 09:30:24.0
celestial bodyhas spectra2001-09-27 09:30:09.0
physical objecthas location or center of gravity2001-09-27 09:27:27.0
has angular momentum2001-09-27 09:27:27.0
has momentum2001-09-27 09:27:27.0
has temperature2001-09-27 09:27:27.0
has volume2001-09-27 09:27:27.0
has extent2001-09-27 09:27:27.0

Kinds of RR Lyrae star :

Uphorizontal branch star, periodic variable