Its head was composed of Lambda, Kappa, Iota, and Phi Andromedae; its hump was Beta Cassiopeiae; its body was the rest of Cassiopeia, and the legs were composed of stars in Perseus and Andromeda. Cassiopeia was the wife of Cepheus, and hence Queen of Aethiopia, in Greek mythology. [17] Magnitude 8.9 yellow dwarf companion (B) is widely separated; companions (C and D) are closer and magnitudes 13 and 14 respectively. M103 is far poorer than M52, with only about 25 stars included. The asterism is oriented as a W when below Polaris during northern spring and summer nights. [36], Two members of the Local Group of galaxies are in Cassiopeia.

Alpha Cassiopeiae was called Poloahilani, Beta Cassiopeiae was called Polula, and Gamma Cassiopeiae was called Mulehu. [3] Its position in the Northern Celestial Hemisphere means that the whole constellation is visible to observers north of 12°S. IC 10 is an irregular galaxy that is the closest known starburst galaxy and the only one in the Local Group of galaxies. [39], The December Phi Cassiopeiids are a recently discovered early December meteor shower that radiates from Cassiopeia. Two Messier objects, M52 (NGC 7654) and M103 (NGC 581), are located in Cassiopeia; both are open clusters. The three-letter abbreviation for the constellation, as adopted by the International Astronomical Union in 1922, is "Cas". Phi Cassiopeiids are very slow, with an entry velocity of approximately 16.7 kilometers per second. [19] It is a Delta Scuti variable with a small amplitude and period of 2.5 hours. The hand is made up of the stars α Cas, β Cas, γ Cas, δ Cas, ε Cas, and η Cas.

Alpha Cassiopeiae, traditionally called Schedar (from the Arabic Al Sadr, "the breast"), is a four-star system. [20], Gamma Cassiopeiae is the prototype Gamma Cassiopeiae variable star, a type of variable star that has a variable disc of material flung off by the high rotation rate of the star.

[5][6], Cassiopeia has been variously portrayed throughout her history as a constellation. [37], IC 10 is an irregular galaxy that is the closest known starburst galaxy and the only one in the Local Group of galaxies. While parts of the constellation technically rise above the horizon to observers between the latitudes of 12°S and 43°S, stars within a few degrees of the horizon are to all intents and purposes unobservable. [4] She was forced to wheel around the North Celestial Pole on her throne, spending half of her time clinging to it so she does not fall off, and Poseidon decreed that Andromeda should be bound to a rock as prey for the monster Cetus.

The Heart Nebula and the Soul Nebula are two neighboring emission nebulae about 7,500 light-years away. It has around 450 times the Sun's diameter and 17 times its mass, having begun life 45 times as massive as the Sun.

In France, she was portrayed as having a marble throne and a palm leaf in her left hand, holding her robe in her right hand.

[35], NGC 457 is another open cluster in Cassiopeia, also called the E.T.