Cepheid variable stars

Cepheid variable stars are a type of star that pulsates, changing in brightness over time. This fluctuation occurs in a regular cycle, with some stars brightening and dimming every few days or weeks. The key feature of Cepheid variables is that their brightness is directly related to their pulsation period; longer periods indicate greater average luminosity. This relationship allows astronomers to use Cepheid variables as "standard candles" for measuring distances in space, helping map the universe and navigate our understanding of its expansion. Thus, they play a crucial role in the field of astrophysics.