Kappa Ursae Majoris
Kappa Ursae Majoris is a binary star in the constellation of Ursa Major. With a combined apparent magnitude of +3.60, the system is approximately 358 light-years from Earth.
The two components are designated Kappa Ursae Majoris A and B.
Nomenclature
κ Ursae Majoris is the system's Bayer designation. The designations of the two components as Kappa Ursae Majoris A and B derives from the convention used by the Washington Multiplicity Catalog for multiple star systems, and adopted by the International Astronomical Union.A traditional name of the system is Alkafzah, from the Arabic القفزة al-qafzah "the leap ", which refers to an asterism consisting of ι, κ, λ, μ, ν, and ξ Ursae Majoris. The name Alkafzah was also attributed to χ Ursae Majoris. κ and ι Ursae Majoris formed the third leap of the gazelle, and sometimes shared the name Talitha, from Arabic al-thālitha "third", with κ rarely called Talitha Australis, "southern Talitha" in Latin.
In 2016, the IAU organized a IAU [Working Group on Star Names|Working Group on Star Names] to catalog and standardize proper names for stars. The WGSN decided to attribute proper names to individual stars rather than entire multiple systems. It approved the name Alkaphrah for the component Kappa Ursae Majoris A on 5 September 2017 and it is now so included in the List of IAU-approved Star Names. The name Talitha was approved for ι Ursae Majoris.
In Chinese astronomy, 三台, meaning Three Steps, refers to an asterism consisting of Kappa Ursae Majoris, Iota Ursae Majoris, Lambda Ursae Majoris, Mu Ursae Majoris, Nu Ursae Majoris and Xi Ursae Majoris. Consequently, the Chinese name for Kappa Ursae Majoris itself is 上台二.