SkyEye: Cepheus

The King

Abbreviation:	Cep
Genitive:	Cephei
Origin:	[antiquity]
Fully Visible:	1°S – 90°N

In Greek mythology, King Cepheus and Queen Cassiopeia of Æthiopia (what we call the Upper Nile region) had a daughter named Andromeda. Cassiopeia boasted that she and her daughter was more beautiful than the Nereids, the sea nymphs who often accompanied Poseiden, god of the seas. As punishment, Poseiden sent a sea monster, Cetus, to ravage the coast of Æthopia. In desperation, Cepheus consulted an oracle who informed him that to appease Poseiden, Cepheus must sacrifice his daughter Andromeda to the sea monster. Thus, Andromeda was stripped naked and chained to the rocks on the coast of the sea. Fortunately for her, Perseus was passing by, having just slain the Gorgon, Medusa. He killed the sea monster and set Andromeda free, claiming her as his bride.

The constellation of Cepheus

Notable Features

Visible Named Stars
α Cep	Alderamin	Because of axial precession of Earth's axis around the poles, this will be the northern pole star in 7565 CE.
β Cep	Alfirk	A telescope reveals this to be a double star. The brighter of the two stars is the prototype of the class of pulsating variable stars known as β Cephei stars. Alfirk will take its turn as the northern pole star in 5930 CE.
γ Cep	Errai	This star also gets to be the northern pole star, coming to within 2° of the celestial pole in 4145 CE. It is known to have at least one exoplanet. It appears as Erakis (from the Arabic al‑rāqiṣ meaning 'the trotting camel') in Antonín Bečvář's Atlas of the Heavens — Ⅱ Catalogue 1950.0.
ξ Cep	Kurhah	A telescope will reveal this object to be a binary star with an orbital period of several thousand years.
Other Interesting Stars
δ Cep		Although this star has no common name, it is a famous variable star and the prototype of an entire class of objects called Cepheids. Cepheids seen to exhibit a period-luminosity relationship, making them useful for measuring galactic and extra-galactic distances.
μ Cep	Garnet Star	The Garnet Star was so called by William Herschel on account of its deep red colour. It is also varies noticably in brightness over a two year period. The name of the star is not officially recognised by the IAU.
Deep Sky Objects
C1		C1 is one of the oldest known open clusters and lies far above the plane of the galaxy. A telescope is necessary to see it. It is also known by its New General Catalogue number 188.
C2	Bow-Tie Nebula	A telescope will be necessary to see this faint planetary nebula, also called NGC 40.
C4		This seventh magnitude object is a bright reflection nebula. It is also catalogued as NGC 7023.
C9	Cave Nebula	Long-exposure photography is the only way to see this dim and diffuse nebula containing emission, reflection and dark nebulosity regions. It appears in the extended Sharpless catalogue as Sh2-155.
C12	Fireworks Galaxy	NGC 6946 is a spiral galaxy close to the galactic plane of the Milky Way and a telescope is required to see the heavily obscured Fireworks Galaxy.