The constellation of Cassiopeia is a circumpolar constellation which lies on or near the Milky Way. Cassiopeia is made up of five main stars: the irregularly variable stars alpha Cas and gamma Cas, the double star eta Cas, the triple star iota Cas, and the variable star rho Cas. The asterism clearly shows the chair upon which Cassiopeia sits. The "Bayer Stars" are generally of third and fourth magnitude, with the exception of the first four stars which make up the chair. Cassiopeia has been known as the Celestial "W," as well as being called the "Woman of the Chair" by the Romans. To the Arabs, she was the "Lady of the Chair."
The mythology tied to this constellation is quite interesting. Cassiopeia was the legendary queen of Ethiopia, known throughout the land for her elegant beauty. Becoming increasingly vain, Cassiopeia boated that she was even lovelier than the Nereids, the Sea Nymphs (goddesses of unmatched beauty who ruled over nature).
Enraged by Cassiopeia's false bragging, the Sea Nymph's begged the God of the Sea, Poseidon, to punish the queen for her insults and conceit. Poseidon became so angry with Cassiopeia that he unleashed a sea monster, Cetus the Whale, and sent him to destroy the coast of Cassiopeia's homeland.
The Sea Nymphs also sought eternal punishment for Cassiopeia, arranging for her to be placed in the heavens tied to a chair. In the northern sky, Cassiopeia sits, forever circling the celestial pole. At times, she is hanging upside down in a most undignified position as a warning to all.