Question

Hey guys
I need ur help
Answer this pls

A star sometimes appears brighter and some other times fainter. What is this effect called?
State the reason for this effect.

Answer 1

It is due to atmospheric refraction.. I causes due to varying optical densities at various altitudes.

Answer 2

State the reason for this effect. A star sometimes appears brighter and some other times fainter because of twinkling effect. Atmospheric refraction gives rise to twinkling effect. Light which is travelling through different layers of the atmosphere bents in different directions making the stars twinkle.

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