Xi Persei
Xi Persei, formally named Menkib, is a star in the constellation of Perseus. Based upon parallax measurements taken during the Hipparcos mission, it is approximately 1,200 light-years from the Sun.Nomenclature
ξ Persei is the star's Bayer designation.
It bore the traditional name Menkib, Menchib, Menkhib or Al Mankib, from Mankib al Thurayya. In 2016, the International Astronomical Union organized a Working Group on Star Names to catalogue and standardize proper names for stars. The WGSN approved the name Menkib for this star on 12 September 2016 and it is now so included in the List of IAU-approved Star Names.
In Chinese, 卷舌, meaning Rolled Tongue, refers to an asterism consisting of Xi Persei, Nu Persei, Epsilon Persei, Zeta Persei, Omicron Persei and 40 Persei. Consequently, the Chinese name for Xi Persei itself is 卷舌三.Properties
Xi Persei has an apparent magnitude of +4.06 and is classified as a blue giant. It is intrinsically 12,700 times brighter than the Sun with absolute magnitude −5.5 in the V band. If the ultraviolet light that emanates from Menkib is included, its total bolometric luminosity is 263,000 times that of the Sun.
The star has a mass of some 30 solar masses and a surface temperature of 35,000 kelvins, making it one of the hottest stars that can be seen with the naked eye. The fluorescence of the California Nebula is due to this star's prodigious radiation. It is a member of the Perseus OB2 association of co-moving stars, but may be a runaway star since it is now separated by 200 pc from the association's center and has an unusually high radial velocity.
