This is a blue supergiant of spectral type B5 Ia; a massive star that has used up its core hydrogen and expanded into a very luminous star. It has an effective temperature around 15,000 K and is radiating 83,000 times the Sun's luminosity.[8] Several studies of 5 Persei have detected possible small amplitude variations. In 1983, an amplitude of 0.045 magnitudes was measured with a possible period of eight days.[7] An analysis of Hipparcos photometry showed an amplitude of 0.0168 magnitudes and a period of 2.65 days. The statistical signal was strong enough for the variability to be very likely, but 5 Persei has not formally been catalogued as a variable star.[11]
5 Persei has two nearby companions, a 12th magnitude star 5.7 arc-seconds away and a 13th magnitude star one arc-minute away.[12]
^ abcdDucati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237: 0. Bibcode:2002yCat.2237....0D.
^ abGalazutdinov, G.; Strobel, A.; Musaev, F. A.; Bondar, A.; Krełowski, J. (2015). "The Structure and Kinematics of the Galaxy Thin Gaseous Disk Outside the Solar Orbit". Publications of the Astronomical Society of the Pacific. 127 (948): 126. arXiv:1501.01187. Bibcode:2015PASP..127..126G. doi:10.1086/680211. S2CID117822109.
^ abcdeMcErlean, N. D.; Lennon, D. J.; Dufton, P. L. (1999). "Galactic B-supergiants: A non-LTE model atmosphere analysis to estimate atmospheric parameters and chemical compositions". Astronomy and Astrophysics. 349: 553. Bibcode:1999A&A...349..553M.