Lambda Cephei (λ Cephei) is a fifth magnitudeblue supergiant star in the constellation Cepheus, one of the hottest and most luminous visible to the naked eye.
^Sota, A.; Maíz Apellániz, J.; Walborn, N. R.; Alfaro, E. J.; Barbá, R. H.; Morrell, N. I.; Gamen, R. C.; Arias, J. I. (2011). "The Galactic O-Star Spectroscopic Survey. I. Classification System and Bright Northern Stars in the Blue-Violet at R ~ 2500". The Astrophysical Journal Supplement Series. 193 (2): 24. arXiv:1101.4002. Bibcode:2011ApJS..193...24S. doi:10.1088/0067-0049/193/2/24. ISSN0067-0049. S2CID119248206.