Erakis
The famous M-type supergiant variable star designated Mu Cephei has two proper names currently listed in SIMBAD: "Erakis" and "Herschel's Garnet Star". Piazzi partially Latinized the latter in his Palermo atlas (1814) to the "Garnet Sidus". Some recent works have the latter as "Garnet Star" (Burnham 1978; Hoffleit & Warren 1991 Bright Star Catalog, 5th ed.; Ridpath & Tirion 2007) or "The Garnet Star" (Kunitzsch & Smart 2006).
Etymology and History
The etymology of "Erakis" is shared with the name "Alrakis", which WGSN already adopted for the star Mu Draconis A. Becvar appears to have mistakenly attributed a variant of the name (Erakis) to Mu Cephei instead of Mu Draconis, and no evidence for association of the name with Mu Cephei has been found in pre-Becvar works. Becvar's name "Erakis" and association with Mu Cephei only appeared rarely in subsequent works (e.g. Rhoads 1971, Bakich 1995).
Mythology
IAU Working Group Star Names
To reduce confusion in astrophysics research papers, the two names for µ Cep were discussed by the IAU WGSN in 2024 with the goal to decide for one of them.
"Erakis" has a shared etymology with "Alrakis" which WGSN applied to µ Dra A, so a re-application would be a repetition. Furthermore, recent works Burnham 1978; Hoffleit & Warren 1991 Bright Star Catalog, 5th ed.; Ridpath & Tirion 2007) or "The Garnet Star" (Kunitzsch & Smart 2006) prefer the English term "Garnet Star". Therefore, WGSN decided to adopt only this term in the IAU-CSN (and drop the historical alternative "Erakis").
