Suppose that Star X and Star Y both have redshifts, but Star X has a larger redshift than Star Y. What can you conclude?
A) Star X is moving away from us faster than Star Y.
B) Star Y is moving away from us faster than Star X.
C) Star X is hotter than Star Y.
D) Star X is moving away from us and Star Y is moving toward us.
E) Star X is coming toward us faster than Star Y.

Question

Quizplus · Accepted Answer

Redshift is a measure of how much the light from an object is stretched as it travels through space. The greater the redshift, the faster the object is moving away from us. Therefore, if Star X has a larger redshift than Star Y, we can conclude that Star X is moving away from us faster than Star Y.

Suppose That Star X and Star Y Both Have Redshifts