Question

A star sometimes appear brighter an sometimes fainter.what is the effect called?State the reason for.

Answer 1

this effect is called as twinkling of stars. the reason behind it is the continuously changing density of the atmosphere which leads to a continuous change in the refractive index of the atmosphere. inevitably this changes the brightness of the stars.

Answer 2

Answer:

It is because of refraction of emitted light from stars get refracted due to particles present in air and thus it look sometimes brighter and sometimes fainter .