Explanation left|thumb|390x390px|Geometric diagram proving that the angle between the North Celestial Pole and the observer's horizon, i.e., the angle that spans the radius of the circumpolar circle, is equal to the observer's latitude. As Earth rotates daily on its axis, the stars appear to move in circular paths around one of the celestial poles (the north celestial pole for observers in the Northern Hemisphere, or the south celestial pole for observers in the Southern Hemisphere). Stars far from a celestial pole appear to rotate in large circles; stars located very close to a celestial pole rotate in small circles and hence hardly seem to engage in any diurnal motion at all. Depending on the observer's latitude on Earth, some stars – the circumpolar ones – are close enough to the celestial pole to remain continuously above the horizon, while other stars dip below the horizon for some portion of their daily circular path (and others remain permanently below the horizon).
explanation left|thumb|390x390px|g:eometric diagram proving that the an.gle between the north celestial pole and the observer's :horizon ie the angle that spans the radius of the circumpolar circle is equal to the observer's latitude as earth rotates daily on its axis the stars appear to move in circular paths around one of the celestial poles (the north celestial pole for observers in the northern hemisphere or the south celestial pole for observers in the southern hemisphere) stars far from a celestial pole appear to rotate in large circles; stars located very close to a celestial pole rotate in small circles and hence hardly seem to engage in any diurnal mo.tion at all depending on the observer's latitude on earth some stars – the circumpolar ones – are close enough to the celestial pole to remain continuously above the horizon while other stars dip below the horizon for some portion of their daily circular path (and others remain permanently below the horizon)