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

If therefore Ilioneus, according to our supposition, understand the heliacal rising of Orion, Anna must mean the achronical, which the different epithets given to that constellation seem to manifest.

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

In Egypt, another reason was, that then the Nile began to overflow, at the heliacal rising of Sirius.

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

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

The first day of the Muhammadan month Jamada' l akhir, corresponding to the heliacal rising of the moon on that occasion, was Saturday, May 19.

From A Forgotten Empire (Vijayanagar): a contribution to the history of India by Sewell, Robert

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