Answer:
shift the wavelength of spectral lines
Explanation:
The Doppler effect is commonly used in the field of astronomy to study the motion of astronomical objects such as a star, planets, and distant galaxies. This results in the changing of wavelength and shifting of the spectral lines, due to the relative and continuous motion of the receiver and the source. This is known as the red-shifting, where the lights in the spectrum move towards the highest wavelength, i.e towards the red light. This Doppler effect signifies that the distance between the distant galaxies and earth increases with the increasing recessional velocity.
