Nomenclature
- Latin: Cepheus
- Genitive: Cephei
- Abbreviation: Cep
- Greek: Κηφεύς Kepheus
- Arabic: Qīfāws
The Latin and Arabic terms for the constellation are mere transliterations of the Greek form, which itself was just the name of the King of Ethiopia.
Description
Cepheus is one of the northernmost of the constellations, his feet extending all the way onto the tail of Ursa Minor. His head lies in between the stars δ & μ Cep. δ Cep in particular is quite notable, as it is the prototype star for the Cepheid class of variable stars, used prolifically in cosmic distance ladder measurements.
Along with his family members and Orion, he is one of the few constellations mentioned by their human names. As such, there is little ambiguity as to his association in antiquity.
Within Cepheus lies the asterism of the House, the base formed by the quadrangle of Alderamin (α), Alfirk (β), ι, & ζ Cep and the roof formed by the triangle of Alfirk (β), Errai (γ), & ι Cep. The two brightest stars of Cepheus, Alderamin and Alfirk, and their positioning within the House may be remembered by the following mnemonic: "All the firken ramen is in the house!"
Mythology
Cepheus
Cepheus was the mythological King of Ethiopia in the tale of Perseus. According to Euripedes, he was the son of Pheonix, husband of Cassiopeia, and father of Andromeda.
The vainglorious Cassiopeia once claimed she was more beautiful than the Nereids, a slight that the 50 sea-nymphs did not take lightly. As Amphitrite, wife of Poseidon, numbered among them, they bade the God of the Ocean to punish Cassiopeia for her blasphemy. Poseidon then wrought Cetus, the Sea Monster, upon Cepheus's kingdom. The Oracle of Ammon then instructed Cepheus to chain his daughter Andromeda to a cliff in sacrifice to evade the total destruction. Perseus, on a fly-by of the kingdom after his slaying of Medusa, saw the chained Andromeda and immediately fell for her. He freed her in exchange for her hand in marriage, a prize which complicated things for Cepheus as Andromeda was already betrothed to his brother Phineus. Thus, Phineus and his men ambushed Cepheus and Perseus at the wedding banquet of the latter, resulting in a bloody battle. Cepheus fled the scene after a time, leaving Perseus to cut his way through his adversaries. Eventually, he brandished the Head of Medusa to subdue the rest Phineus's men, turning them to stone.
Perseus and Andromeda stayed in Ethiopia for a time, their union resulting in the boy Perses who was given to Cepheus to raise as he had no son to succeed him. The pair then made their way back to Greece where Perseus's adventures eventually concluded.
The family of Cepheus features prominently in the northern sky. Cassiopeia was catasterised by Poseidon, bound to a chair and her upper half dunked into the ocean with every celestial rotation, a quite undignified eternity. Perseus and Andromeda were then placed into the sky by Athena on account of the former's heroism, to whom she also added the figure of Cepheus to allow him the company of his family for eternity. Evidently, Cepheus was determined fit for the skies on account of his pedigree as a descendent of Zeus by Io.
Stars
| Name | Designation | Apparent Magnitude |
|---|---|---|
| Alderamin | α Cep | 2.46 |
| Alfirk | β Cep | 3.23 |
| Errai | γ Cep | 3.28 |
| Garnet Star | µ Cep | 4.08 |
| Kurhah | ξ Cep | 4.45 |
| Tarandus | HIP 5372 | 4.22 |
Sources
- Ridpath, Ian. Star Tales. link.
- Lafitte, Roland. Catalogue of Star Names Created in the Greco-Arabian Sky. link.
- Grant, Mary. The Myths of Hyginus (1960). Accessed via link.
- Condos, Theony. Star Myths of the Greeks and Romans: A Sourcebook (1997), pp. 83-84. link.
- Hard, Robin. Eratosthenes and Hyginus, Constellation Myths with Aratus's 'Phaenomena' (2015), pp. 66-69. link.
- IAU WGSN. IAU-Catalog of Star Names (CSN). link.
- Stellarium Contributors. Stellarium Astronomy Software. link.