The brighter the star is overall, the longer the period of luminosity. Since the cepheids in the Magellanic Clouds were all about the same distance from Earth, Leavitt concluded that the period ...
133, No. 1026, 2021 August Observational and Theoretical Studies of... Observational and Theoretical Studies of 27 δ Scuti Stars with Investigation of the Period–Luminosity Relation This is the ...