Understanding Circumpolar Bodies || Principle of Navigation || Celestial Navigation скачать в хорошем качестве

Understanding Circumpolar Bodies || Principle of Navigation || Celestial Navigation

In celestial navigation, circumpolar bodies are stars (or other celestial objects) that, because of your latitude, never set below the horizon—they seem to circle endlessly around the celestial pole. Key Points • Definition: A circumpolar star stays permanently above the observer’s horizon and appears to trace a full circle around the North Celestial Pole (Northern Hemisphere) or South Celestial Pole (Southern Hemisphere). • Dependence on Latitude: o The closer you are to the pole, the larger the circumpolar region. o At the North Pole, every visible star is circumpolar. o At the equator, no star is circumpolar—everything rises and sets. • Why Useful in Navigation: o They provide constant reference points for azimuth (direction) because they never dip below the horizon. o Polaris (the North Star) is the best-known circumpolar star for Northern Hemisphere mariners—it’s always roughly due north and its altitude ≈ observer’s latitude. • Southern Hemisphere: Lacks a bright “South Pole Star,” but constellations like the Southern Cross and surrounding stars can act as circumpolar references. In short, circumpolar bodies are permanently visible guide stars, especially valuable for steady bearings and latitude checks when other stars rise and set.