| the polestar or North Star, a star of the second magnitude close to the north pole of the heavens, in the constellation Ursa Minor |
| the gaseous envelope surrounding a heavenly body |
aphelion (æpˈhiːlɪən, əˈfiː-) ![]() | |
| —n , pl -lia | |
| Compare perihelion the point in its orbit when a planet or comet is at its greatest distance from the sun | |
| [C17: from New Latin aphēlium (with pseudo-Greek ending -ion) from | |
| ap'helian | |
| —adj | |
aphelion (ə-fē'lē-ən) Pronunciation Key
(click for larger image in new window) The point at which an orbiting body, such as a planet or comet, is farthest away from the Sun. Compare apogee, perihelion. |