What type of star is RR Lyrae?
Q: What type of star is RR Lyrae?
A: RR Lyrae is a pulsating variable star in the constellation Lyra. It is the model for the variable stars known as RR Lyrae variables.
Q: How long does it take for RR Lyrae to pulse?
A: RR Lyrae pulses over a short cycle of 13 hours, 36 minutes.
Q: What is the radius of RR Lyrae compared to that of the Sun?
A: Each radial pulsation causes the radius of the star to vary between 5.1 and 5.6 times the Sun's radius.
Q: Where are stars like RR Lyrae typically found?
A: Stars of this type are often found in globular clusters.
Q: What type and mass are these stars?
A:RR Lyrae and its type are pulsating stars of spectral class A (and rarely F), with a mass of around half the Sun's.
Q: How do they compare to Cepheid variables?
A:RR Lyraes pulse in a manner similar to Cepheid variables, so the mechanism for the pulsation is thought to be similar; however, unlike Cepheids, they are old, low mass, metal-poor "Population II" stars which are much less luminous than Cepheids on average.
Q: How was their distance determined in 2002?
A: In 2002, their distance was fixed within a 5% margin of error using measurements from Hubble Space Telescope combined with those from Hipparcos satellite and other sources; resulting in an estimated distance 860 light-years (260 parsecs).
