Heliacal

 WORD OF THE DAY

heliacal / adjective / hih-LYE-uh-kul

Definition
: relating to or near the sun — used especially of the last setting of a star before and its first rising after invisibility due to conjunction with the sun

Examples
"Early sky watchers kept watch on the heavens in their attempts to correlate celestial and terrestrial activity and noticed that, during this brutally hot season, the star Sirius rose around the same time as the sun (its 'heliacal rising,' as we call it today), and the two moved across the daytime sky together."
— Dennis Mammana, The Noozhawk (Santa Barbara, California), 9 Aug. 2020

"Throughout the ancient world, the reappearance of Sirius in the morning dawn was a significant event. In Egypt, its heliacal rising coincided with the annual flooding of the Nile River, as well as the most oppressive period of desert heat, including a greater frequency of thunderstorms brought about by a monsoon effect from the Red Sea."
— David L. DeBruyn, The Muskegon (Michigan) Chronicle, 25 Aug. 2019

Did You Know?
The word heliacal rose in the mid-16th century. Its source is the Greek word hēlios, meaning "sun."
Helios is also the Sun god of ancient Greece.
Heliacal often suggests a relationship between a star and the sun as they appear to the human eye in the sky.
It is also used in reference to the ancient Egyptian year, which began on the date when Sirius (or the Dog Star) first appeared on the eastern horizon at sunrise.
English speakers have referred to this year as the heliacal year or the Sothic year. (Sothic comes from "Sōthēs," the Greek word for Sirius.)