Question

If the redshift of star A is 10% greater than that of star B, what can you conclude about the two stars? (Assume the redshifts of both stars are positive.)

(a) Star A is moving away from us slower than star B.
(b) Star A is moving toward us slower than star B.
(c) Star A is moving toward us faster than star B.
(d) Star A is moving away from us faster than star B.
(e) Either (b) or (d).

Answer 1

Star A, with a redshift 10% greater than star B's, is moving away from us faster than star B, due to the Doppler effect on light.

Step-by-step explanation:

If the redshift of star A is 10% greater than that of star B and assuming that the redshifts of both stars are positive, it can be concluded that star A is moving away from us faster than star B. This follows from the understanding of the Doppler effect, where an increase in redshift corresponds to an increase in the velocity at which an object is receding from the observer. Therefore, the correct answer is (d) Star A is moving away from us faster than star B.