what is pole star? why does it appears to be stationary? plzz give me the answer in short
Keep it up, good answering @ Singhapoorva and Saumya.
Pole star is a visible star in the constellation of Ursa Minor (also called lesser bear or Saptarshi Mandal).
Pole star does not seem to change its position because it is very near to the axis of rotation of earth. But as axis of rotation of earth is itself changing over a large period of time (called precision), thus the current polar star would be replaced by other stars in the distant future.
a pole star is a visible star, especially a prominent one, that is approximately aligned with the Earth's axis of rotation; that is, a star whose apparent position is close to one of the celestial poles, and which lies approximately directly overhead when viewed from the Earth's North Pole or South Pole.
it appears to be stationary because it's located only a half a degree from the North Celestial Pole (NCP). This is the point in the night sky where the projection of the Earth's axis lies. In other words, a huge column extending from the geographic North Pole up into space would just miss the North Star.
Since the Earth rotates around this axis, it stands to reason that in the Northern Hemisphere, the North Star appears stationary, while other constellations revolve around it.
hope it helps....