heliacal rising

British  

/ hɪˈlaɪəkəl /

noun

1. the rising of a celestial object at approximately the same time as the rising of the sun

2. the date at which such a celestial object first becomes visible in the dawn sky

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Etymology

Origin of heliacal rising

C17: from Late Latin hēliacus relating to the sun, from Greek hēliakos, from hēlios the sun

Example Sentences

See Examples For:

heliacal rising

It seems to have been considered of great importance in ancient Egypt, as its heliacal rising announced that of Sirius, which heralded the annual rising of the Nile.

From Astronomical Curiosities Facts and Fallacies by Gore, J. Ellard

They approximated to the truth in reference to the solar year, by observing the equinoxes and solstices, and the heliacal rising of particular stars.

From The Old Roman World, : the Grandeur and Failure of Its Civilization. by Lord, John

According to an extremely ancient belief it was the goddess Hathor Isis-Sothis who caused the inundation of the Nile which, according to the inscriptions, coincided with the heliacal rising of Sirius.

From The Fundamental Principles of Old and New World Civilizations by Nuttall, Zelia

The heliacal rising of Orion is at present computed to be about the 6th of July; and about that time it is that he either causes or presages tempests on the seas.

From Discourses on Satire and on Epic Poetry by Dryden, John

Either the calendar did not originate in Egypt, or it was introduced in 2780 B.C., when again the heliacal rising Sothis fell on the first of Thoth.

From The Egyptian Conception of Immortality by Reisner, George Andrew