HELIACAL

heliacal, heliac

(adjective) pertaining to or near the sun; especially the first rising of a star after and last setting before its invisibility owing to its conjunction with the sun; “the heliacal rising of the Dog Star”; “the heliacal or Sothic year is determined by the heliacal rising of Sothis (the Egyptian name for the Dog Star)”

Source: WordNet® 3.1

Etymology

Adjective

heliacal

(rare) Of or relating to the Sun, especially rising and setting with the sun.

Of or relating to the rising of a star when it first becomes visible just before sunrise in the eastern sky, having previously been made invisible by sunlight, or the analogous situation of its setting just after sunset.

Anagrams

• achillea

Source: Wiktionary

He*li"a*cal, a. Etym: [Gr. héliaque.] (Astron.)

Definition: Emerging from the light of the sun, or passing into it; rising or setting at the same, or nearly the same, time as the sun. Sir T. Browne.

Note: The heliacal rising of a star is when, after being in conjunction with the sun, and invisible, it emerges from the light so as to be visible in the morning before sunrising. On the contrary, the heliacal setting of a star is when the sun approaches conjunction so near as to render the star invisible.

Source: Webster’s Unabridged Dictionary 1913 Edition