A form of pulsation in which a star expands and contracts symmetrically over its whole surface. The changes in radius are accompanied by variations in brightness, surface temperature, and spectrum. The majority of giant and supergiant variables (e.g. Cepheid variables, Mira stars, RR Lyrae stars, RV Tauri stars, and semiregular variables) pulsate in this manner. See also non-radial pulsation.
Subjects: Astronomy and Astrophysics.