in fabulous history, wife to Cepheus, king of Ethiopia, and mother of Andromeda. She thought herself more beautiful than the Nereides, who desired Neptune to revenge the affront; so that he sent a sea monster into the country, which did much mischief. To appease the god, her daughter Andromeda was exposed to the monster, but was rescued by Perseus, who obtained leave of Jupiter that Cassiopeia might be placed after her death among the stars; and hence the constellation of that name.

Astronomy, one of the constellations of the northern hemisphere, situated next to Cepheus. In 1572 there appeared a new star in this constellation, which at first surpassed in magnitude and brightness Jupiter himself; but it diminished by degrees, and at last disappeared at the end of eighteen months. It alarmed all the astronomers of that age, many of whom, as Tycho Brahe, Kepler, Maurolycus, Lycetus, and Gramineus, wrote dissertations on it. Beza the landgrave of Hesse, Rosa, and others, wrote to prove it a comet, affirming that it was the same which had appeared to the Magi at the birth of Jesus Christ, and that it came to declare his second coming: they were answered on this subject by Tycho.