1. A class of variable stars that brighten and dim in a regular, periodic pattern; used as distance markers in astronomy.
Usage: astronomy; plural of cepheid; named after the star Delta Cephei

Examples

• Astronomers use cepheids to measure distances to nearby galaxies.
• The brightness variations of cepheids follow a predictable pattern.
• Edwin Hubble discovered cepheids in the Andromeda Galaxy, proving it was a separate galaxy.
• Cepheids are important standard candles in cosmology.
• The period-luminosity relationship of cepheids allows scientists to calculate their true brightness.