The Book of Nut (original title: "The Fundamentals of the Course of the Stars") is a collection of ancient Egyptian astronomical texts, also covering various mythological subjects. These texts focus on the cycles of the stars of the decans, the movements of the moon, the sun, and the planets, on the sundials, and related matters. This title was given to the book because of the depiction of the sky goddess Nut arching over the earth in some copies of the text. She is supported by the god of the air Shu. Texts in the Book of Nut include material from different periods of Egyptian history.