Pulsating variables are stars that are continuously expanding and contracting and therefore show variations in brightness 例如脈動變星就是恒星本身不斷膨脹收縮,造成光度亦出現相應的變化。
Pulsating variables vary periodically , but for some stars , there may be sudden changes in their brightness . such kinds of stars are called eruptive variables . they include :脈動變星的光度會周期性地改變,但有一些恒星的光度會在毫無先兆下變得光芒萬丈,這種恒星包括新星和超新星皆統稱為爆發變星。