Why do stars twinkle?

AcademicPhysicsNCERTClass 10

Twinkling of stars in the sky$\rightarrow$

The twinkling of stars is merely an optical illusion. In reality, stars do not twinkle, they just seem to be twinkling, because of atmospheric refraction.

Reasons for the twinkling of stars$\rightarrow$

Stars are visible to us through several layers of the atmosphere that vary in density and temperature, due to this turbulence in the atmosphere, the light coming from the stars undergoes refraction in a continuous manner until it reaches the Earth. Sometimes they appear brighter and sometimes they appear fainter. Thus, they seem to be twinkling. The very small angular displacement in their image due to the variable wind index causes them to twinkle. 

The below picture is given to illustrate how stars seem to twinkle due to the refraction of light as it passes through the turbulent atmosphere and on the earth's surface appears as it is twinkling.

twinkling of stars

Updated on 10-Oct-2022 13:22:12