Beta Cephei

Beta Cephei is a triple star system in the northern constellation of Cepheus. Its name is a Bayer designation that is Latinized from β Cephei, and abbreviated Beta Cep or β Cep. This system is a visible to the naked eye as a point of light with a combined apparent visual magnitude that ranges from 3.16 to 3.27, making it a third magnitude star. Based on parallax measurements obtained during the Hipparcos mission, it is approximately 690 light-years distant from the Sun. It is the prototype of the Beta Cephei variable stars.

It consists of a binary pair (designated Beta Cephei A) together with a third companion (B). The binary's two components are themselves designated Beta Cephei Aa (officially named Alfirk, the traditional name for the system) and Ab.