Cassiopeia is one of the most recognizable constellations in the northern sky. Its distinctive 'W' shape, formed by five bright stars, makes it easy for stargazers to spot throughout the year. Cassiopeia was named after the vain queen of Aethiopia in Greek mythology, who boasted about her beauty and was immortalized among the stars as punishment.
The constellation has been known since antiquity and was catalogued by the Greek astronomer Ptolemy in the 2nd century. In modern astronomy, Cassiopeia remains one of the 88 recognized constellations by the International Astronomical Union.
Cassiopeia is a circumpolar constellation for observers at latitudes above 34°N—it never sets below the horizon. Its brightest stars, Alpha Cassiopeiae (Schedar), Beta Cassiopeiae (Caph), Gamma Cassiopeiae (Navi), Delta Cassiopeiae (Ruchbah), and Epsilon Cassiopeiae (Segin), form the iconic ‘W’ or ‘M’ shape depending on its orientation in the sky.
The constellation is rich in deep-sky objects. Notable among them are the open star clusters Messier 52 and Messier 103, which can be observed with binoculars or small telescopes. The supernova remnant Cassiopeia A—one of the strongest radio sources in the sky—also lies in its borders.
In mythology, Cassiopeia is typically depicted sitting on her throne, sometimes holding a mirror. She features in the legend of Perseus and Andromeda, her daughter, who was chained to a rock as punishment for Cassiopeia's pride.