Question

You observe a nearby galaxy. You find that a spectral line, resulting from an electron transition in hydrogen, is shifted from its normal location in the red part of the spectrum into the orange part of the spectrum. What can you conclude?

Answer 1

Answer:

The galaxy is moving closer to us

Explanation:

When there is a decrease in the wavelength of light which is being observed then it means that the object and observer are getting closer to each other.

When there is an increase in the wavelength of light which is being observed then it means that the object and observer are getting farther apart.

This phenomenon is called the Doppler effect.

Orange has shorter wavelength than red so the wavelength is getting shorter.

Hence, the galaxy is moving closer to us.