Cepheid variable(redirected from Period-luminosity relationship)
Related to Period-luminosity relationship: Cepheid variable star
(Astronomy) astronomy any of a class of variable stars with regular cycles of variations in luminosity (most ranging from three to fifty days). There is a relationship between the periods of variation and the absolute magnitudes, which is used for measuring the distance of such stars
a variable star with a short period of 1 to 50 days in which changes in brightness are due to alternations in volume.