The constellation Cetus

The constellation Cetus

The constellation Cetus is a constellation of the southern hemisphere. Its brightest star is β Ceti, which bears the Arabic name Deneb Kaitos (tail of the monster).

Its best-known star, however, is ο Ceti (Mira – the wonderful one). It is located at the neck of the whale and roughly every eleven months (332 days) it shines almost as brightly as the Pole Star. Mira is a red giant whose brightness varies between different levels, from the 2nd to the 9th magnitude. When Mira is at the 2nd magnitude, it can be seen very well with the naked eye, while from the 7th magnitude onwards binoculars are needed. At the 9th magnitude, it can only be seen with a telescope.

Mythology

According to Greek mythology, Cepheus was the king of Ethiopia. He was a descendant of the nymph Io, who was a lover of Zeus. Cepheus was married to the vain Cassiopeia, who boasted everywhere that she was even more beautiful than the Nereids, the fifty daughters of the sea god Nereus. In response, the sea god Poseidon, who was married to one of the Nereids, sent the sea monster Cetus to the coast of Cepheus's kingdom. Cepheus turned to the oracle of Ammon for help. The oracle told him to chain his daughter Andromeda to a rock and sacrifice her to the monster. Only in this way could the destruction off his coast be stopped. In his despair, Cepheus followed the oracle's advice. However, Andromeda was rescued just in time by the hero Perseus. Perseus then asked for Andromeda's hand in marriage. Although Andromeda had already been promised to her uncle Phineus, Cepheus agreed. In the end, a fight broke out between Perseus and Phineus at the wedding celebration. During this fight, Perseus held out the head of Medusa towards Phineus. Phineus was turned to stone on the spot.

Cepheus, Cassiopeia, Andromeda, Perseus and the monster Cetus (whale) were later placed in the sky as constellations.