Variable Star

Any star whose brightness or magnitude varies with time. The variations can be intrinsic because of internal processes or extrinsic, due to eclipses, dust and other phenomena. Variations can also be irregular or periodic. There are many sorts of variable stars, including Cataclysmic, Cepheid, Extrinsic, Eruptive, Intrinsic, Irregular, Long-Period, Regular, and Semi-Regular.