Twinkling stars in the sky
Why does stars twinkle class 10
Why do stars twinkle short answer class 10
When we look at stars,quite often they do not appear to shine steadily.They disappear for a fraction of a second before reappearing(the intensity of light from them fluctuates),or their positions seem to shift slightly in random direction.We call this the twinkling of stars.
twinkling of stars is due to which phenomenon
Explanation
Since the tempereture of air and its humidity are not the same everywhere in the atmosphere,the refractive index of air varies between different masses of air, even at the same altitude.Thus, there exist air masses whose refractive index is different from that of the air surrounding it,when a ray light passes through such a mass of air,it bends due to refraction.light from a stars may pass through one or more air masses before reaching the eye.But the air masses keep moving.So,the direction of the ray reaching the eye keeps changing,causing the image of the star to shift in random directions or even disappear for an instant.The amount of starlight reaching the eye also keeps changing due to the shift in the direction of the light.So,the brightness of the star seems to change.
The satrs near the horizon twinkle more than those that are overhead.This is because light from a star near the horizon has to cover much more distance in the atmosphere than that from stars which are overhead.Therefore,it has greater chances of encountering air masses density is different from the surrounding air.
