heliacal rising


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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.
References in periodicals archive ?
It is the first day that it is visible in the morning sky that marks the heliacal rising of a star.
Heliacal rising, as described above is something that happens to stars, not to constellations.
Since the festival occurred soon after the beginning of the month, we propose that the heliacal rising of Delphinus was the signal that the next New Moon would begin the month of Apollo Delphinios.
Thera's Delphinios was known not to be in a sailing season (Trumpy 1997:186-7), which does correlate with the heliacal rising of Delphinus, but then so would many other periods.
Delphinios also astronomically matches, given the proximity of Delphinus's heliacal rising to the solstice.
Finally, Luft presents a short essay on the absolute date for the heliacal rising of Sothis in year 7 of Sesostris III recorded in the Lahun archive.
159) from Uruk establishes "correspondences between the liver examined by the haruspex and the heliacal risings of constellations.
The stars don't move their real positions perceptibly within an individual's lifetime and cannot therefore give dates unless heliacal risings or settings were marked, and alignments are not essential for determining these.