InChinese astronomy, Zeta Cassiopeiae is called 附路,Pinyin: Fùlù, meaningAuxiliary Road, because this star is marking itself and standing alone in theAuxiliary Roadasterism,Legs (mansion) (seeChinese constellation).[12] 附路 (Fùlù) was westernized intoFoo Loo, but that name was also designated forEta Cassiopeiae by R.H. Allen, with the meaning of "a by-path"[13] In 2016, the IAU organized aWorking Group on Star Names (WGSN)[14] to catalog and standardize proper names for stars. The WGSN approved the nameFulu for Zeta Cassiopeiae on 30 June 2017 and it is now so included in the List of IAU-approved Star Names.[11]
Zeta Cassiopeiae is a B2subgiant, indicating that it has exhausted its core hydrogen and started toevolve away from themain sequence. It has a temperature of over 20,000 K, is about eight times the massof the sun, and is 7,200 timesas luminous.
Zeta Cassiopeiae is a probable member of an unusual group of variable stars known as "Slowly Pulsating B" (SPB) stars.[16] It shows a pulsation frequency of 0.64 per day (or once every 1.56 days) and displays a weakmagnetic field with a strength of roughly3.35 × 10−2T, which varies with a period of 5.37 days.[17] This likely matches the rotation rate of the star, which, when combined with the lowprojected rotational velocity, indicates the star may be seen nearly pole-on. Zeta Cassiopeiae is a candidate magneticBp star that shows an overabundance of helium. The star contains a randomly orientedfossil magnetic field, which impacts the outflow of the stellar wind. Collisions between streams from this stellar wind creates a shock front, with cooling particles settling toward a co-rotating disk.[18]
^abJohnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars",Communications of the Lunar and Planetary Laboratory,4 (99): 99,Bibcode:1966CoLPL...4...99J
^Jaschek, C.; Gomez, A. E. (1998). "The absolute magnitude of the early type MK standards from HIPPARCOS parallaxes".Astronomy and Astrophysics.330: 619.Bibcode:1998A&A...330..619J.
^abcdMaestro, V.; Che, X.; Huber, D.; Ireland, M. J.; Monnier, J. D.; White, T. R.; Kok, Y.; Robertson, J. G.; Schaefer, G. H.; Brummelaar, T. A. T.; Tuthill, P. G. (2013), "Optical interferometry of early-type stars with PAVO@CHARA - I. Fundamental stellar properties",Monthly Notices of the Royal Astronomical Society,434 (2): 1321,arXiv:1306.5937,Bibcode:2013MNRAS.434.1321M,doi:10.1093/mnras/stt1092,S2CID2361434
^Gordon, Kathryn D.; Gies, Douglas R.; Schaefer, Gail H.; Huber, Daniel; Ireland, Michael (March 2019), "Angular Sizes, Radii, and Effective Temperatures of B-type Stars from Optical Interferometry with the CHARA Array",The Astrophysical Journal,873 (1): 91,Bibcode:2019ApJ...873...91G,doi:10.3847/1538-4357/ab04b2,S2CID125181833
^Gies, Douglas R.; Lambert, David L. (March 1992), "Carbon, nitrogen, and oxygen abundances in early B-type stars",Astrophysical Journal, Part 1,387:673–700,Bibcode:1992ApJ...387..673G,doi:10.1086/171116
