The heliacal rising of Sothis returned to the same point in the calendar every 1, 460 years ( a period called the " Sothic cycle " ).
22.
Every 8 years, Venus passes Spica around the time of the star's heliacal rising, as in 2009 when it passed 3.5?north of the star on November 3.
23.
The heliacal rising occurs when the sun has moved far enough past the star that the star rises and becomes visible before the sun rises in the morning.
24.
In the ancient Egyptian calendar, the date of the annual inundations of farm land by the Nile river was predicted by observing the heliacal rising of a star.
25.
The coincidence of a heliacal rising of Sirius and the New Year reported by Censorinus occurred about the 20th of July, that is a month later after the summer solstice.
26.
These were used in the ancient Egyptian calendar, which was based on lunar cycles of around 30 days and on the heliacal rising of the star Sothis ( Sirius ).
27.
The ancient Egyptians used the heliacal rising of Sirius ( i . e ., the day on which the star first became visible above the eastern horizon just before dawn ).
28.
Its heliacal rising also presaged the appearance of " Matariki " ( the Pleiades ) in the dawn sky which marked the Mori New Year in late May or early June.
29.
"' Sirius "'is the their calendar on the heliacal rising of Sirius, namely the day it becomes visible just before sunrise after moving far enough away from the glare of the Sun.
30.
In fact, according to calculations made on the basis of the heliacal rising of the star Sirius ( Sothis ) and inscriptions found by archaeologists, this date must have been October 22.
