How did Harlow Shapley use the period-luminosity relationship of Cepheid variables to determine the size of the Milky Way galaxy?
A) He determined the proper motion of globular clusters in the outer disk of the galaxy.
B) He found the distance to individual Cepheid variables free floating in the halo.
C) He found the distance to open clusters found throughout the disk of the galaxy.
D) He found the distance to globular clusters distributed about the center of the galaxy.

Question

Quizplus · Accepted Answer

Harlow Shapley used the period-luminosity relationship of Cepheid variables to measure the distance to globular clusters, which are distributed around the center of the Milky Way. By determining these distances, he was able to estimate the size of the galaxy and the position of the Sun within it.

How Did Harlow Shapley Use the Period-Luminosity Relationship of Cepheid