Alpha Phoenicis (α Phoenicis, abbreviated Alpha Phe or α Phe), formally named Ankaa (distinguish

Ancha Theta Aquarii (θ Aquarii, abbreviated Theta Aqr, θ Aqr), officially named Ancha (distinguish Ankaa, with the same pronunciation), is a star in the equatorial constellation of Aquarius. Visible to the naked eye at apparent magnitude 4 ...

, with the same pronunciation) is the brightest star in the constellation of Phoenix.

Nomenclature

''Alpha Phoenicis'' is the star's

Bayer designation A Bayer designation is a stellar designation in which a specific star is identified by a Greek or Latin letter followed by the genitive form of its parent constellation's Latin name. The original list of Bayer designations contained 1,564 stars. ...

. It also bore the traditional name Ankaa sometime after 1800, from the

Arabic Arabic (, ' ; , ' or ) is a Semitic languages, Semitic language spoken primarily across the Arab world.Semitic languages: an international handbook / edited by Stefan Weninger; in collaboration with Geoffrey Khan, Michael P. Streck, Janet C ...

العنقاء ''al-ʽanqāʼ'' "the phoenix" for the name of the constellation. Medieval Arab astronomers formed the constellation of the dhow (where Phoenix is), so another popular name for the star is ''Nair al Zaurak'' from نائر الزورق''nayyir az-zawraq'' "the bright (star) of the skiff". The Latin translation is ''Cymbae,'' from ''lūcida cumbae''. In 2016, the

International Astronomical Union The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreac ...

organized a

Working Group on Star Names The International Astronomical Union (IAU) established a Working Group on Star Names (WGSN) in May 2016 to catalog and standardize proper names for stars for the international astronomical community. It operates under Division C – Education ...

(WGSN) to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016 included a table of the first two batches of names approved by the WGSN; which included ''Ankaa'' for this star. In

Chinese Chinese can refer to: * Something related to China * Chinese people, people of Chinese nationality, citizenship, and/or ethnicity **''Zhonghua minzu'', the supra-ethnic concept of the Chinese nation ** List of ethnic groups in China, people of va ...

caused by adaptation of the European southern hemisphere constellations into the Chinese system, (), meaning ''

Firebird Firebird and fire bird may refer to: Mythical birds * Phoenix (mythology), sacred firebird found in the mythologies of many cultures * Bennu, Egyptian firebird * Huma bird, Persian firebird * Firebird (Slavic folklore) Bird species ''Various spe ...

'', 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 (, en, the Sixth Star of Firebird.)AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 27 日
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Description

This is a

spectroscopic binary A binary star is a system of two star, stars that are gravity, gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved using a telescope as separa ...

star system with components that orbit each other every 3848.8 days (10.5 years). The combined

stellar classification In astronomy, stellar classification is the classification of stars based on their stellar spectrum, spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a Prism (optics), prism or diffraction grati ...

of the system is K0.5 IIIb, which matches the

spectrum A spectrum (plural ''spectra'' or ''spectrums'') is a condition that is not limited to a specific set of values but can vary, without gaps, across a continuum. The word was first used scientifically in optics to describe the rainbow of colors i ...

of a normal luminosity giant star. It has an apparent visual magnitude of 2.4, so it is somewhat outshined by its first magnitude neighbors

Achernar Achernar is the brightest star in the constellation of Eridanus, and the ninth-brightest in the night sky. It has the Bayer designation Alpha Eridani, which is Latinized from α Eridani and abbreviated Alpha Eri or α Eri. The name A ...

(α Eridani) and Fomalhaut (α Piscis Australis). Based upon

parallax Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight and is measured by the angle or semi-angle of inclination between those two lines. Due to foreshortening, nearby objects ...

measurements, this system is at a distance of about from the

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

. The

interferometry Interferometry is a technique which uses the ''interference'' of superimposed waves to extract information. Interferometry typically uses electromagnetic waves and is an important investigative technique in the fields of astronomy, fiber opt ...

-measured

angular diameter The angular diameter, angular size, apparent diameter, or apparent size is an angular distance describing how large a sphere or circle appears from a given point of view. In the vision sciences, it is called the visual angle, and in optics, it is ...

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 Solar radius is a unit of distance used to express the size of stars in astronomy relative to the Sun. The solar radius is usually defined as the radius to the layer in the Sun's photosphere where the optical depth equals 2/3: :1\,R_ = 6.957\t ...

. Ankaa is similar to many of the visible stars of the night sky, being an orange giant of relatively average stellar size. It is currently thought to be in the midst of a short but stable

helium Helium (from el, ἥλιος, helios, lit=sun) is a chemical element with the symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas and the first in the noble gas group in the periodic table. ...

burning phase of its

stellar evolution Stellar evolution is the process by which a star changes over the course of time. Depending on the mass of the star, its lifetime can range from a few million years for the most massive to trillions of years for the least massive, which is cons ...

, although it probably will not be long in astronomical terms before it sheds its outer layers as a planetary nebula and ends its life quietly as a

white dwarf A white dwarf is a stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very dense: its mass is comparable to the Sun's, while its volume is comparable to the Earth's. A white dwarf's faint luminosity comes fro ...

. Ankaa has a small stellar companion, about which little is known.

References

{{Stars of Phoenix Phoenicis, Alpha K-type giants Phoenix (constellation) Spectroscopic binaries

Ankaa Alpha Phoenicis (α Phoenicis, abbreviated Alpha Phe or α Phe), formally named Ankaa (distinguish Ancha, with the same pronunciation) is the brightest star in the constellation of Phoenix. Nomenclature ''Alpha Phoenicis'' is the st ...

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