The chief cult centre of Ra was Heliopolis (called Iunu, "Place of Pillars", in Egyptian), where he was identified with the local sun-god Atum. Through Atum, or as Atum-Ra he was also seen as the first being and the originator of the Ennead, consisting of Shu and Tefnut, Geb and Nut, Osiris, Set, Isis and Nephthys.
Ra was thought to travel on two solar boats called the Mandjet (the Boat of Millions of Years), or morning boat and the Mesektet, or evening boat. These boats took him on his journey through the sky and the underworld. When Ra traveled in his sun boat he was accompanied by various other deities including Sia (perception) and Hu (command) as well as Heka (magic power). Sometimes members of the Ennead helped him on his journey, including Set who overcame the serpent Apophis and Mehen who defended against the monsters of the underworld.
Apophis, an enormous serpent tried to stop the sun boat's journey every night by consuming it or by stopping it in its tracks with a hypnotic stare. In the evening the Egyptians believed that Ra set as Atum or in the form of a ram. The Mesektet or Night boat would carry him through the underworld and back towards the east in preparation for his rebirth. These myths of Ra represent the sunrise as the rebirth of the sun by the sky.>>
The following was true both in 10,700 BC AND 2550 BC (as it is true today):
Alnilam to Alnitak: ~ 45º NW => SE vis-a-vis annual Ra celestial W => E ecliptic solar path.
Khafre (2532? BC) to Khufu (2560 BC): ~ 45º SW => NE vis-a-vis daily Ra underground W => E solar path.
Alnitak: ~ 25.3º S of annual Ra celestial W => E solar path. (i.e., 25.3º S of Ecliptic)
Khufu: ~ 25.3º N of daily Ra underground W => E solar path 12 days before autumnal equinox
<<Season of the Harvest (known in Egyptian as Shemu or Shomu) is the third and final season of the Egyptian calendar. The word Shemu literally translates as "low-water", and falls roughly between early May and early September. The months of the lunar calendar are roughly equivalent to the period from early May to the heliacal rising of Sirius around the beginning of September.>>