Ra first appears as the grandson of Rat (herself considered an earlier, female version of Ra and later his wife; other names for her include Eus-os, Iusas, and Uert-Hekeu). In this version, he is son to Nu and Nut, over whose arched back he travels daily, beginning his journey at dawn as a baby and finishing at dusk as an old man. Later, he superseded his grandmother Rat, and according to the priests of Sais, was the son of Neith or Net, a virgin goddess and herself self-begotten. She was a goddess of war, possibly of Libyan origin, who may be equated with Pallas Athene. She was popular during the twenty-sixth dynasty but was later confused with Hathor and Isis. According to the Heliopolis grouping of gods, Ra was a member of the Ennead (the Nine Gods of Heliopolis) and father to Osiris, Isis, Set, and Nephthys by Nut. He is said to have created humanity from his tears.
Ra is also referred to as Ra-Tem (equated with Atmu, a local god of Heliopolis), Atum, Atum-Re or Re-Atum, Amun or Amun-Ra, and Re-Khepri. He is represented as a divine black bull (Mnevis or Mer-wer) or a falcon, wearing the solar disk and uraeus (snake) on his head. By day, he is depicted sailing through the sky in his celestial boat (the Mantchet). In the evening as his boat (the Mesektet) passes through the western gate, he is called Tum and is old and frail. Af or Auf is the name of Ra as he makes his nightly journey along the river Urnes in Tuat (or Duat), "the Fields of Peace," battling the serpents of the underworld. He is accompanied on this journey by Watchman, Striker, and Steersman, along with other gods who have the ability to combat the demons of evil through arcane incantation. Hu and Saa are children of Ra who appears in the sun god's boat at the Creation and during the Judgement of the Dead.
Af or Auf literally means ‘corpse.’ He is a manifestation of Ra as the dead sun god during his passage through the underworld. At the end of each day, Ra would die and embark on his night journey as Auf. Unlike his Ra counterpart, Auf was depicted with a ram’s head.
Because there was no wind in the underworld, Auf had to rely on various demons and gods for help in towing his ship. He stood in his deckhouse over which the serpent Mehen coiled, warding off the dangerous Apep. Auf’s boat was crewed by the gods Hu, Saa and Wepwawet. His main job in the Underworld was to bring light to the souls of the dead as he passed through their realm. After his return to the land of the living, these souls fell back into a lonely darkness.
There is also a sun god of the Pacific Islands named Ra.