The Sun disc itself, first as a heavenly body, later personified as Re. During the Amarna period exalted by Akhenaten (Amenhotep IV) to be the only god in existence, something which had been unheard of in Egyptian religion. Aten was then depicted as a sundisc with rays ending in life-giving hands. This period was brief, only ca 15 years and may in fact not have had any large effect outside of the royal court. After Akhenaten´s death the priesthood of Amun reinstalled the old religious practice and the Amarna period became an exception in the history of Ancient Egypt.
Main center of worship:
Akhet-aten - Tell el-Amarna, 14th N, Upper Egypt
Festival Days: (dates not historically verified)
21st of July - 3rd of Thuti - Birthday of Aten