The Egyptian culture placed a great importance on the heliacal rising of Sirius. This heliacal rising is the
first time in the year when Sirius was seen in the sky just before sunrise. This rising of Sirius (known by
the Egyptians as Sothis) signaled the beginning of festivals celebrating fertility and renewal. It also roughly
coincided with the annual flooding of the Nile, thus also marking the beginning the growing season. The
Egyptian year was divided into 36 ten day weeks, called Decans, plus five days at the end of the year to
make 365, (for HS a discussion of leap year stuff) just as we have.
Within each Decan a star was identified to measure each of the twelve intervals of the passage through the
underworld of Ra, the Egyptian sun god. The Egyptians named this interval an hour, for which hieroglyph
for is a star. The ancient Egyptian astronomers had no need of watches, the stars told them the time! The
Decans and the stars associated with them form the earliest known system of constellations.
The Egyptian culture placed a great importance on the heliacal rising of Sirius. This heliacal rising is the
first time in the year when Sirius was seen in the sky just before sunrise. This rising of Sirius (known by
the Egyptians as Sothis) signaled the beginning of festivals celebrating fertility and renewal. It also roughly
coincided with the annual flooding of the Nile, thus also marking the beginning the growing season. The
Egyptian year was divided into 36 ten day weeks, called Decans, plus five days at the end of the year to
make 365, just as we have.
Within each Decan a star was identified to measure each of the twelve intervals of the passage through the
underworld of Ra, the Egyptian sun god. The Egyptians named this interval an hour, for which hieroglyph
for is a star. The ancient Egyptian astronomers had no need of watches, the stars told them the time! The
Decans and the stars associated with them form the earliest known system of constellations.
