[4] Cassiopeia A is a supernova remnant and the brightest extrasolar radio source in the sky at frequencies above 1 GHz.

A rich section of the Milky Way runs through Cassiopeia, containing a number of open clusters, young luminous galactic disc stars, and nebulae.

[5] 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.

In Persia, she was drawn by al-Sufi as a queen holding a staff with a crescent moon in her right hand, wearing a crown, as well as a two-humped camel.

[6] In Chinese astronomy, the stars forming the constellation Cassiopeia are found among three areas: the Purple Forbidden enclosure (紫微垣, Zǐ Wēi Yuán), the Black Tortoise of the North (北方玄武, Běi Fāng Xuán Wǔ), and the White Tiger of the West (西方白虎, Xī Fāng Bái Hǔ).

These included Bathsheba, Solomon's mother; Deborah, an Old Testament prophet; and Mary Magdalene, a follower of Jesus.

[6] A figure called the "Tinted Hand" also appeared in the stars of Cassiopeia in some Arab atlases.

The people of Pukapuka saw the figure of Cassiopeia as a distinct constellation called Na Taki-tolu-a-Mataliki.

[12] The official constellation boundaries, as set by Belgian astronomer Eugène Delporte in 1930,[b] are defined by a polygon of 30 segments.

[3] Its position in the Northern Celestial Hemisphere means that the whole constellation is visible to observers north of 12°S.

[14] The German cartographer Johann Bayer used the Greek letters Alpha through Omega, and then A and B, to label the most prominent 26 stars in the constellation.

In northern winter, and when seen from southern latitudes, it is "above" Polaris (i.e. closer to the zenith) and the W appears inverted.

Alpha Cassiopeiae, traditionally called Schedar (from the Arabic Al Sadr, "the breast"), is commonly mistaken as a four-star system, but is actually a single star with three physically distant optical components.

[17] With a luminosity of around 771 times that of the Sun, it has swollen and cooled after exhausting its core hydrogen over its 100 to 200 million-year lifespan, spending much of it as a blue-white B-type main-sequence star.

[19] Beta Cassiopeiae, or Caph (meaning "hand"), is a white-hued star of magnitude 2.3, 54.7±0.3 light-years from Earth.

[17] Around 1.2 billion years old, it has used up its core hydrogen and begun expanding and cooling off the main sequence.

This is giving the star an oblate spheroid shape with an equatorial bulge that is 24% larger than the polar radius.

It is a spectroscopic binary, with an orbital period of 203.59 days and a companion with a calculated mass about the same as the Sun.

However, no direct evidence of this companion has been found, leading to speculation that it might be a white dwarf or other degenerate star.

Delta Cassiopeiae, also known as Ruchbah or Rukbat, meaning "knee," is a possible Algol-type eclipsing binary star with a maximum brightness of magnitude 2.7.

[28] Its magnetic field and wind of particles creates a visible bow shock 4 light-years ahead of it, colliding with the diffuse, and usually invisible, interstellar gas and dust.

[29] Theta Cassiopeiae, named Marfak, is a suspected variable star whose brightness changes by less than a tenth of a magnitude.

[31] It is visually located between Alpha and Gamma Cassiopeiae and are one of the nearest G-type / K-type stars to Earth.

[23] Rho Cassiopeiae is a semi-regular pulsating variable yellow hypergiant, and is among the most luminous stars in the galaxy at approximately 500,000 L☉.

It also hosts the red supergiant PZ Cassiopeiae, which is one of the largest known stars with an estimate of 1,190–1,940 R☉ and is also a semiregular variable.

A rich section of the Milky Way runs through Cassiopeia, stretching from Perseus towards Cygnus, and it contains a number of open clusters, young luminous galactic disc stars, and nebulae.

NGC 457 is looser, and its brightest member is Phi Cassiopeiae, a white-hued supergiant star of magnitude 5.0.

As a result of this location in the Zone of Avoidance, both are surprisingly faint despite both being within 10 million light-years away (Maffei 2 is below the range of most amateur telescopes).

[45] USS Cassiopeia (AK-75) was a United States Navy Crater-class cargo ship named after the constellation.

Although the lyrics of the song mainly refer to the ancient Greek woman, the album cover shows the constellation.