Question

What happens to light waves from a star as the star moves toward Earth?A. They appear to shift toward red.B. They appear to shift toward blue.C. They appear to become mechanical waves.D. They appear to stop.

Answer 1

When a star moves toward or away from the earth, the light will be in a slightly different place in the spectrum from where a start would be at rest.

Due to the doppler effect, if a star moves toward the earth, the star's spectral lines will make a shift toward the blue end of the spectrum.

Therefore, the light waves from a star as the star moves toward the earth will appear to shift toward blue.

ANSWER:

B. They appear to shift toward blue.