Alpha Phoenicis


Alpha Phoenicis, formally named Ankaa, is the brightest star in the constellation of Phoenix.

Nomenclature

Alpha Phoenicis is the star's Bayer designation. It also bore the traditional name Ankaa sometime after 1800, from the Arabic العنقاء al-ʽanqāʼ "the phoenix" for the name of the constellation. The International Astronomical Union has formally adopted the Ankaa as the proper name for Alpha Phoenicis.
Medieval Arab astronomers formed the constellation of the dhow, so another popular name for the star is Nair al Zaurak from نائر الزورق nayyir az-zawraq "the bright of the skiff". The Latin translation is Cymbae, from lūcida cumbae.
In Chinese caused by adaptation of the European southern hemisphere constellations into the Chinese system, 火鳥, meaning Firebird, refers to an asterism consisting of α Phoenicis, ι Phoenicis, σ Phoenicis, ε Phoenicis, κ Phoenicis, μ Phoenicis, λ1 Phoenicis, β Phoenicis and γ Phoenicis. Consequently, α Phoenicis itself is known as 火鳥六

Description

Alpha Phoenicis is a spectroscopic binary star system with components that orbit each other every 3,848.8 days. The combined stellar classification of the system is K0.5 IIIb, which matches the spectrum of a normal luminosity giant star. It has an apparent visual magnitude of 2.4, so it is somewhat outshone by its first magnitude neighbors Achernar and Fomalhaut. Based upon parallax measurements, this system is at a distance of about from the Earth. The interferometry-measured angular diameter of the primary component, after correcting for limb darkening, is, which, at its estimated distance, equates to a physical radius of about 15 times the radius of the Sun.