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

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

This period, measured thus by the heliacal rising of Sothis, is spoken of as the Sothic cycle.

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

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)

I do not see how the heliacal rising of Sirius in any one year could help them to determine its length.

From Personal Recollections, from Early Life to Old Age, of Mary Somerville by Somerville, Mary

Brugsch states that the appearance of the said new moon, which was also associated with the heliacal rising of Sirius, would range from Aug.

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