A pole star is a visible star that is approximately aligned with the axis of rotation of an astronomical body; that is, a star whose apparent position is close to one of the celestial poles. On Earth, a pole star would lie directly overhead when viewed from the North or the South Pole.
Northern Hemisphere circumpolar stars around Polaris, with a long-exposure producing a star trail photo
A method to find the Pole star Polaris at 5x the distance of the two front stars of the Big Dipper.
Circle of southern stars, Chile, 2016
Rotation or rotational motion is the circular movement of an object around a central line, known as axis of rotation. A plane figure can rotate in either a clockwise or counterclockwise sense around a perpendicular axis intersecting anywhere inside or outside the figure at a center of rotation. A solid figure has an infinite number of possible axes and angles of rotation, including chaotic rotation, in contrast to rotation around a fixed axis.
Star trails caused by the Earth's rotation during the camera's long exposure time