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

In about a month, followed the Stars of the Husbandman; the chief of them, Ras, Mirach, and Arcturus, being very nearly simultaneous in their heliacal rising.

From Morals and Dogma of the Ancient and Accepted Scottish Rite of Freemasonry by Pike, Albert

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 Beacon Lights of History, Volume 03 Ancient Achievements by Lord, John

The Egyptians had, at an early period, observed that the rising of the Nile coincided with the heliacal rising of Sirius, the Dog-star, and hence they very plausibly referred it to celestial agencies.

From History of the Intellectual Development of Europe, Volume I (of 2) Revised Edition by Draper, John William

This is what is technically known as the "acronical rising" of the Pleiades, their rising at sunset; in contrast to their "heliacal rising," their rising just before daybreak, which ushered in the spring time.

From The Astronomy of the Bible An Elementary Commentary on the Astronomical References of Holy Scripture by Maunder, E. Walter (Edward Walter)