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Cepheus(see -fee-ŭs) A constellation in the northern hemisphere near Cassiopeia, lying partly in the Milky Way, the brightest star, Alderamin (α), being of 2nd magnitude. As a result of precession, both Alderamin and the 3rd-magnitude Alrai (γ) have come close enough to the north celestial pole to serve as pole stars and will do so again. Cepheus contains several pulsating variable stars, including the prototype Cepheid variable Delta (δ) Cephei, the red irregular variable Mu (μ) Cephei or Garnet star, and the prototype of the Beta Cephei stars. Abbrev.: Cep.; genitive form: Cephei; approx. position: RA 22h, dec +70°; area: 588 sq deg.
a constellation in the northern hemisphere. Its brightest star, Alderamin, has a visual stellar magnitude of 2.4. The star δ Cephei was the first star to be classified as a cepheid variable. The best conditions for observing Cepheus prevail from July through September. The constellation is visible everywhere in the USSR year-round.