A star moving toward the Sun will show:
A) a shift in the spectral lines toward the blue end (as compared to the laboratory positions of these lines)
B) a significant increase in its apparent brightness (magnitude)
C) more and more helium lines as it approaches us
D) a shift in the spectral lines toward the red end (as compared to the laboratory positions of these lines)
E) no change that can be measured with our present-day instruments

Question

Quizplus · Accepted Answer

A shift in the spectral lines toward the blue end (blue shift) occurs because the wavelengths of light are compressed as the star moves toward the observer, which is consistent with the Doppler effect.

A Star Moving Toward the Sun Will Show