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heliacal rising
heliacal rising (hɪˈlaɪəkəl) n1. (Astronomy) the rising of a celestial object at approximately the same time as the rising of the sun2. (Astronomy) the date at which such a celestial object first becomes visible in the dawn sky[C17: from Late Latin hēliacus relating to the sun, from Greek hēliakos, from hēlios the sun]heliacal rising
heliacal rising (hi-lÿ-ă-kăl) The first appearance of a star or planet in the eastern sky just before dawn, following a period when it has been too close to the Sun to be visible. A heliacal setting is the last occasion on which a star or planet can be seen in the western sky just after sunset prior to its becoming too close to the Sun to be seen.heliacal rising[hi′lī·ə·kəl ′rīz·iŋ] (astronomy) The rising of a celestial body at the same time or just before that of the sun. |