Geodesy Board Practice Exam

Circumpolar stars are those that never set at a given latitude because their daily path around the sky stays above the horizon. As the Earth rotates, stars circle the celestial poles. If a star is close enough to the pole, the lowest point of its diurnal circle never drops below the horizon, so it remains visible all year. Practically, this depends on your latitude: the closer you are to the pole, the more stars stay circumpolar; toward the equator, fewer or none do. The rule is that a star is circumpolar at a given latitude if its distance from the celestial pole is small enough that the horizon never cuts its path. The other terms aren’t standard descriptions for this behavior; they don’t convey the idea of a star permanently remaining above the horizon due to proximity to the pole.