Learn how to say Cephei correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word Cepheus:
a constellation near the north celestial pole, with no very bright stars.
(as genitive Cephei /ˈsiːfɪʌɪ/) used with preceding letter or numeral to designate a star in this constellation:
the star Beta Cephei
from the name of a king of Ethiopia, the husband of Cassiopeia