These describe an Assyrian system that grew out of what was known as the “Three Stars Each” tradition. They contain a summary of most of the Babylonian astronomical knowledge from before the seventh century BCE. The word “Apin” means “plough,” referring to the constellation Triangulum. The coverage of the planets is less than for the Moon and stars.
Some of the contents are as follows:
- Improvements to the older lists of the stars of Ea, Anu, and Enlil;
- Lists of stars that rise while others set;
- Lists of periodicity of visibility of certain stars;
- Lists of secondary stars (ziqpu);
- Reports of lunar eclipses no later than the seventh century BCE;
- A list of eighteen constellations in the path of the Moon;
- A statement that the Sun, the Moon, and five planets were considered to move on the same path;
- A list showing, by mathematical calculations, when the shadow of a vertical rod (gnomon) one cubit high is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 cubits long at various seasons;
- Rules for calculating the rising and the setting of the Moon.