Question

why star appears to be twinkling​

Answer 1

Stars do not really twinkle, they just appear to twinkle when seen from the surface of Earth. The stars twinkle in the night sky because of the effects of our atmosphere. When starlight enters our atmosphere it is affected by winds in the atmosphere and by areas with different temperatures and densities.

Answer 2

Answer:

Due to Refraction of light emited by star.As they are very far from us they appear as a point sized source of light.