Why do stars twinkle?

Stars are laminating balls of plasma that are existing in that shape due to gravity. They consist of chemicals that constantly undergo thermonuclear fusion and releases energy. This released energy will move along inside the start space and as well as radiates out.  Due to the highest brightness delivered by the Sun’s light all other stars are invisible in the day time and are visible in the night sky if it is not clouded.

So the light given out by the stars is due to their self emission. When this light reaches us on the surface of the earth, it has to pass through various layers of earth’s atmosphere. During this journey it is disturbed by the movement of cold and warm air waves existing in the atmosphere of earth. This phenomenon is scientifically termed as refraction of light. Due to refraction of light by the air turbulence the small changes in the timing of the light ray reaching the human eye will vary. Also the refraction will make us to visualize the star to have moved a little. This illusion of the star movement will appear to us as if it is twinkling. If the star is nearer to the Horizon then we can observe more twinkling. But if it is right over our head very nearer to us then the twinkling can be observed as comparatively less. This twinkling cannot be seen in the case of planets as they are massive as well as nearer to us when compared to stars. Moreover, planets are not self emitting celestial bodies. They shine due to Sun’s light falling on them while stars are self emitting bodies due to energy released in them by nuclear fusion. Sun will not twinkle as it is very big in size than other stars.