Who first noticed that for Cepheid variable stars there was a direct relationship between the luminosity and the period of the variation in their brightness?
A)Annie Cannon
B)Edwin Hubble
C)Harlow Shapley
D)Henrietta Leavitt

Question

Quizplus · Accepted Answer

Henrietta Leavitt first noticed the relationship between the luminosity and period of Cepheid variable stars while working at the Harvard College Observatory in the early 1900s. This relationship became known as the period-luminosity relationship and was later used by Edwin Hubble to measure the distances to galaxies.

Who First Noticed That for Cepheid Variable Stars There Was