What is the "rotation curve" of a galaxy?
A) It is a graph of the orbital velocities at various distances from the center of the galaxy.
B) It is a graph of the speed at the center of the galaxy.
C) It is the recession speed of galaxies at various distances from the Milky Way.
D) It is the speed of the globular clusters in a galaxy.

Question

Quizplus · Accepted Answer

The "rotation curve" of a galaxy is a graph that shows how the orbital velocity of stars and other objects in the galaxy varies with their distance from the galaxy's center.

What Is the "Rotation Curve" of a Galaxy