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Cepheus is a northern constellation named after Cepheus, King of Aethiopia in Greek mythology, and is considered to represent a king. It is one of the 88 modern constellations, and was also one of the 48 listed by Ptolemy. Cepheus can be spotted as a box with a triangle on top. Notable features γ Cephei is a binary star approximately 50 light years away from Earth. The system consists of an orange subgiant and a red dwarf. Due to the precession of the equinoxes, γ Cephei will be the pole star between 3000 and 5200 CE, with the closest approach to the north celestial pole around 4000 CE. The primary component is orbited by a planet. δ Cephei is the prototype Cepheid variable. It was discovered to be variable by John Goodricke in 1784. It varies between 3.5m and 4.3m over a period around 5.4 days. There are three red supergiants in the constellation that are visible to the naked eye μ Cephei is known as Herschel's Garnet Star due to its deep red colour. It is a semiregular variable star that varies between 3.4m and 5.1m over a period of 730 days. The star is around 11.8 AU in radius. If it were placed at the centre of our Solar System, it would extend to the orbit of Saturn. Like μ Cep, VV Cephei is also variable, ranging from 4.8m and 5.4m over a period around 20 years. The third red supergiant is HR 8164, whose apparent magnitude is 5.66m. Each of the stars are among the largest known. Kruger 60 is a 10th magnitude binary star consisting of two red dwarfs. The star system is one of the nearest being only 13 light years away from Earth. Notable deep sky objects NGC 188 is an open cluster that has the distinction of being the closest open cluster to the north celestial pole, as well as one of the oldest known open clusters. The Fireworks Galaxy (NGC 6946) is a spiral galaxy in which eight supernovae have been observed, more than in any other galaxy. The nebula NGC 7538 is home to the largest yet discovered protostar. Mythology When including fainter stars, visible to the naked eye, Cepheus appears with a crown (upside down with respect to the ecliptic). Together with other constellations nearby (Andromeda, Perseus, Cassiopeia, and possibly Pegasus), and the constellation Cetus below Cepheus, this may be the source of the myth of the Boast of Cassiopeia, with which it is usually identified.
References * Ian Ridpath and Wil Tirion (2007). Stars and Planets Guide Links
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, Collins, London. ISBN 978-0007251209. Princeton University Press, Princeton. ISBN 978-0691135564.