Definition of cepheid in English:


(also cepheid variable)


  • A variable star having a regular cycle of brightness with a frequency related to its luminosity, so allowing estimation of its distance from the earth.

    • ‘Using this, astronomers only needed to know the period of a cepheid variable to figure out how bright, and therefore how far away it was.’
    • ‘The size and age of the expanding Universe is calculated by astronomers on the basis of winking stars called cepheids, the nearest of which is 1000-2000 light years away.’
    • ‘Shapley also pointed out in that paper that the noted increase in the distance of the clouds explains the ‘failure of the persistent Harvard searches for cluster-type cepheids in the Magellanic Clouds and their globular clusters.’’
    • ‘Several hundred cepheid variables are known in our Galaxy.’
    • ‘Type I cepheids are most closely associated with the thin disc and the spiral arm components of the Galaxy.’


Early 20th century: from the name of the variable star Delta Cephei, which typifies this class of stars.