Due to atmospheric refraction, the stars seem to be higher in the sky than the actual. Due to continuous refraction Light from a star is refracted as it leaves space and enters the earth's atmosphere. Air higher up in the sky is rarer but that nearer the earth's surface is denser. When the light from a star comes down, the dense air bends the light more.
Due to continuous refraction of star's light, the star appears to be at a higher position and our eye will see the star at that position from where light enters it in the straight line direction.