Is the position of a star as seen by us its true position. Justify your answer.
No.
Light emitted by distant stars (act as point sources of light) passes through the atmosphere of the earth before reaching our eyes. The atmosphere
of the earth is not uniform but consists of many layers of different densities. The layers close to the surface of the earth are optically denser. As we
go higher and higher, the density of layers and refractive index decreases progressively. As the light from a star enters the uppermost layer of the
atmosphere, it bends towards the normal as it enters the next layer. This process continues till the light enters our eyes. So due to refraction of
light, the apparent position of the star is different from the actual position of the star (Figure 13).
