The location of the Galactic Center was first found by Harlow Shapley with:
A)radio emissions from Sagittarius A.
B)Cepheids of Population I in the spiral arms.
C)RR Lyrae variables in the globular clusters.
D)planetary nebulae in the open clusters.
E)infrared observations of the heat from its accretion disk around the black hole.

Question

Quizplus · Accepted Answer

Harlow Shapley determined the location of the Galactic Center in the early 20th century by studying the distribution of globular clusters and their RR Lyrae variable stars. He noticed that these clusters were not evenly distributed across the sky but were instead concentrated in the direction of the constellation Sagittarius, leading him to conclude that the center of the Milky Way galaxy lies in that direction.

The Location of the Galactic Center Was First Found by Harlow