Leavitt's work with variable stars led to her most important contribution to the field: the cepheid variable period-luminosity relationship. By intense observation of a certain class of variable star, the cepheids, Leavitt discovered a direct correlation between the time it took a star to go from bright to dim to how bright it actually was. This relationship enabled astronomers, such as Edwin Hubble, to make groundbreaking discoveries about the distance to the galaxies and the expansion of the universe.

Miss Leavitt's Statement

Cepheid Stars