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

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 a constellation is when it comes from under the rays of the sun, and begins to appear before daylight.

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

Swart star: the Dogstar, called swarthy because its heliacal rising in ancient times occurred soon after mid-summer. moist vows: either tearful prayers, or prayers for one at sea.

From The Golden Treasury Of the Best Songs and Lyrical Poems in the English Language by Palgrave, Francis Turner

The more precise fixing of new year's day was accomplished through observation of the time of the so-called heliacal rising of the dog-star, Sirius, which bore the Egyptian name Sothis.

From A History of Science — Volume 1 by Williams, Edward Huntington

We recognize to-day this "heliacal rising" of the stars.

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