Cepheid variable

== English == === Etymology === From Latin Delta Cephei, the first such star identified. From Cepheus, the name of the constellation in which such stars were first discovered. From being a star with variable brightness. === Noun === Cepheid variable (plural Cepheid variables) (astronomy) A radially pulsating (expanding and contracting) variable star with a regular period and known relationship between period and intrinsic brightness. ==== Translations ====