Question

why the star seem higher then its actual position

Answer 1

As the light rays from a star pass through the different layers of atmosphere (density of layers increasing downwards), they suffer atmospheric refraction from a rarer to a denser medium. ... Due to continuous refraction, the light from the star appears to come from a point which is actually higher than thestar.

Answer 2

They appear to be point source because of their being a very large distance from us. As the desity of air increases with lowering height above the surface of the earth, the Refractive index also increases. star light coming towards us travels from rarer medium to denser medium and constantly bends towards the normal. This makes the star appear to be higher.