heliacal rising

/ 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

Word History and Origins

Origin of heliacal rising¹

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

Example Sentences

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

From Project Gutenberg

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

From Project Gutenberg

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

From Project Gutenberg

This was based upon the heliacal rising of Sirius (Sothis) coincident with the beginning of the inundation.

From Project Gutenberg

Swart star: the Dogstar, called swarthy because its heliacal rising in ancient times occurred soon after mid-summer.

From Project Gutenberg