heliacal

Implying hereby the Heliacal ascent and Cosmical descent of those stars.

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

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

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

They also possessed lists of the fixed stars, and drew up tables of the times of their heliacal risings.