1. The star light goes under atmospheric refraction before reaching the earths surface.2. The atmosphere is made up of particles oc dust, smoke, water droplets and air molecules. Hence the starlight travels from rearer medium to denser madium.3. Thus the apparent position of star is alightly upward than its actual position.4. Also, the stars are point sized sources of light which are located far away from earth. Hence the stars appear to be twinkling.
Because stars are far away from earth and due to atmospheric refraction that twinkles and as we know our Earth is not stationery When earth moves atmosphere also changes and there will be changed in its refractive index also
It\’s principle is atmospheric refraction ?