Cetus is one of the 48 constellations described by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations defined by the International Astronomical Union. Its name refers to Cetus, a sea monster in Greek mythology. Cetus may have originally been associated with a whale, which would have had mythic status amongst Mesopotamian cultures. It is often now called the Whale, though it is most strongly associated with Cetus the sea monster, who was slain by Perseus as he saved the princess Andromeda from Poseidon's wrath. A Celestial Atlas (1822) by Alexander Jamieson, inspired by the star atlas of Johann Elert Bode, but restricted itself to stars that could be seen with the naked eye. Comprising a systematic display of the heavens in a series of thirty maps illustrated by scientific description of their contents and accompanied by catalogues of the stars and astronomical exercises, plate 23, 1822.