CETUS

, the Whale, a southern constellation, and one of the 48 old asterisms. The Greeks pretend that it was the sea-monster sent by Neptune to devour Andromeda, but was killed by Perseus.

In the neck of the whale is a remarkable star, Collo Ceti, which appears and disappears periodically, or rather grows brighter and fainter by turns, owing it is supposed to the alternate turning of its bright and dark sides towards us, as it revolves upon its axis, or else owing to the star having a flattish form. The period of its changes is about 312 days. Bullialdus in Phil. Trans. vol. 2, Hevelius ibid. vol. 6, Herschel ibid. vol. 70, Marald. in Mem. Acad. 1719.

The stars in the constellation Cetus, in Ptolomy's catalogue, are 22, in Tycho's 21, in Hevelius's 45, and in the Britannic catalogue 97.