Question

what does it mean when an emission line of helium from a galaxy is shifted toward red? (1 point)

the galaxy contains a small percent of hydrogen.

the galaxy is moving away from the viewer.

the galaxy contains a large percent of hydrogen.

the galaxy is moving toward the viewer.

Explanation:

This is based on the Doppler effect in astronomy: a redshift of spectral lines occurs when a celestial object moves away from the observer, stretching the light waves to longer (redder) wavelengths. Hydrogen content does not cause this specific redshift shift.

Answer:

The galaxy is moving away from the viewer.