Located in the northern sky, Cassiopeia is a constellation named after the vain queen Cassiopeia in Greek mythology. In Greek mythology, Cassiopeia was vain as she boasted about her unrivaled beauty. Cassiopeia was one of the 48 constellations listed by the 2nd-century Greek astronomer Ptolemy, and is easily recognizable because of 5 stars forming a distinctive ‘W’ shape.

As part of its location in the northern sky, Cassiopeia is visible rom latitudes above 34°N for the entire year. Covering 598.4 square degrees and hence 1.451% of the sky, Cassiopeia ranks 25th of the 88 constellations in area

At magnitude 2.2, Alpha Cassiopeiae, or Schedar, is generally the brightest star in Cassiopeia, though it is occasionally outshone by the variable Gamma Cassiopeiae, which has reached magnitude 1.6. The constellation hosts some of the most luminous stars known. 14 star systems have been found to have exoplanets. A rich section of the Milky Way runs through Cassiopeia, containing a number of open clusters, young luminous galactic disc stars, and nebulae.

	Applicable Information
Visibility In Pacific Northwest	Year Round
Best Times To View	November
Right Ascension	22h 57m 04.5897s–03h 41m 14.0997s
Declination	77.6923447°–48.6632690°
Area	598 square degrees
Main Stars	5
Brightest Object	α Cas
Meteor showers	Perseids
Messier objects	2
Neighboring Constellations	Camelopardalis, Cepheus, Lacerta, Andromeda, Perseus

Mythology

The constellation is named after Cassiopeia, the queen of Aethiopia. Cassiopeia was the wife of King Cepheus of Aethiopia and mother of Princess Andromeda. Cepheus and Cassiopeia were placed next to each other among the stars, along with Andromeda. She was placed in the sky as a punishment after enraging Poseidon with the boast that her daughter Andromeda was more beautiful than the Nereids. 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 Chinese astronomy, the stars forming the constellation Cassiopeia are found in 3 different areas.

Welsh Mythology uses the name of Llys Dôn, which translates to literally “The Court of Dôn” for the constellation.

Some atlases in the Arab world called the stars of Cassiopeia a figure called the “Tinted Hand,” while other Arab constellations did incorporate the stars of Cassiopeia. This constellation was known as the Camel.

Other cultures see a hand or moose antlers in the pattern. Some in the Marshall Islands saw Cassiopeia as part of a great porpoise constellation.

Stars

Johann Bayer labelled the 26 most prominent stars in the constellation. Within its borders, 157 stars brighter than or equal to apparent magnitude 6.5 have been found and catalogued.

The W shaped asterism of Cassiopeia is formed by the 5 brightest stars of the constellation. All five stars of the asterism are prominent naked eye stars, as three stars are variable, and a fourth is a suspected low amplitude variable. The asterism is oriented as a W when below Polaris during northern spring and summer nights.

Stretching from Perseus to Cygnus, some of the Milky Way runs through Cassiopeia, which means that in Cassiopeia there are several interesting objects. This includes open clusters, galactic disc stars, and nebulae.

Neighboring emission nebulae called the Heart Nebula and the Soul Nebula are known for the shape that the dust forms in images. The Heart and Soul nebulae are barely visible in small telescopes and are best seen photographically. These are popular targets for astrophotographers.

The 2 Messier objects of Cassiopeia are M52, otherwise known as NGC 7654, and M103, otherwise known as NGC 581, which are both open clusters.

M52 is an open cluster that can be seen from Earth with binoculars. It contains approximately 100 stars and is 5200 light-years from Earth. M103 contains about 25 stars and is easy to find to view. M103 can be viewed with binoculars and telescopes.

Having about 80 stars each, NGC 457 and NGC 663 are open clusters. NGC 457 is sometimes known as the Owl Cluster, the E.T. Cluster or the “Skiing Cluster” by amateur astronomers. NGC 457 is the brightest open cluster in Cassiopeia and can be seen by binoculars and telescopes, but is not visible by the naked eye. NGC 663 has an estimated 400 stars and spans about a quarter of a degree in the sky; moreover, it can reportedly be detected with the unaided eye. The brightest members of NGCC 663 can be viewed with binoculars, although a telescope is recommended for best viewing.

Make sure to check out other articles on the site, including a brief introduction to constellations, other constellation articles, and more!