RR Lyrae star
noun
Astronomy. one of a group of pulsating variable stars found in the halo of the Milky Way, with periods between 1.2 and 30 hours; all have approximately the same luminosity and are therefore used for measuring distances.
Origin of RR Lyrae star
< New Latin: RR (variable star designation) of Lyra
Also called cluster variable.
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Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019