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Alpha Phoenicis
	Location of α Phoenicis (circled)
Observation data; Epoch J2000 Equinox J2000
Constellation	Phoenix
Right ascension	00h 26m 17.06309s
Declination	−42° 18′ 21.7712″
Apparent magnitude (V)	2.377
Characteristics
Spectral type	K0.5 IIIb
U−B color index	+0.903
B−V color index	+1.092
Astrometry
Radial velocity (Rv)	+74.6 km/s
Proper motion (μ)	RA: +176.268 mas/yr ; Dec.: −398.872 mas/yr
Parallax (π)	39.9183 ± 0.7283 mas
Distance	82 ± 1 ly ; (25.1 ± 0.5 pc)
Absolute magnitude (MV)	0.52
Orbit
Period (P)	3848.8 days
Semi-major axis (a)	103.5 m
Eccentricity (e)	0.34
Inclination (i)	128.0±5.4°
Longitude of the node (Ω)	242.8±3.9°
Periastron epoch (T)	2416201.8 HJD
Argument of periastron (ω); (primary)	19.8°
Details
Mass	2.79±0.14 M☉
Radius	14.7 R☉
Luminosity	83 L☉
Surface gravity (log g)	2.53 cgs
Temperature	4,700 K
Metallicity [Fe/H]	−0.73 dex
Rotational velocity (v sin i)	1.0 km/s
Other designations
	Ankaa, Nair al Zaurak, Cymbae, Lucida Cymbae, CD−42°116, FK5 12, GCTP 71.00, HIP 2081, HR 99, HD 2261, LTT 231, SAO 215093.
Database references
SIMBAD	data

Alpha Phoenicis (α Phoenicis, abbreviated Alpha Phe or α Phe), formally named Ankaa /ˈæŋkə/,^[13] with the same pronunciation) 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.^[13] The International Astronomical Union has formally adopted the Ankaa as the proper name for Alpha Phoenicis.^[14]

Medieval Arab astronomers formed the constellation of the dhow (where Phoenix is), so another popular name for the star is Nair al Zaurak^[15] from نائر الزورقnayyir az-zawraq "the bright (star) of the skiff". The Latin translation is Cymbae, from lūcida cumbae.^[15]

In Chinese caused by adaptation of the European southern hemisphere constellations into the Chinese system, 火鳥 (Huǒ Niǎo), 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 (Huǒ Niǎo liù, English: the Sixth Star of Firebird.)^[16]

Description

Alpha Phoenicis is a spectroscopic binary star system with components that orbit each other every 3,848.8 days (10.5 years).^[6] The combined stellar classification of the system is K0.5 IIIb,^[3] which matches the spectrum of a normal luminosity giant star. It has an apparent visual magnitude of 2.4,^[2] so it is somewhat outshone by its first magnitude neighbors Achernar (α Eridani) and Fomalhaut (α Piscis Austrinus). Based upon parallax measurements, this system is at a distance of about 85 light-years (26 parsecs) from the Earth.^[17] The interferometry-measured angular diameter of the primary component, after correcting for limb darkening, is 5.25±0.06 mas,^[18] which, at its estimated distance, equates to a physical radius of about 15 times the radius of the Sun.^[8]

References

^ ^a ^b ^c ^d ^e Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
^ ^a ^b ^c ^d Gutierrez-Moreno, Adelina; et al. (1966), "A System of photometric standards", Publications of the Department of Astronomy University of Chile, 1, Publicaciones Universidad de Chile, Department de Astronomy: 1–17, Bibcode:1966PDAUC...1....1G
^ ^a ^b ^c ^d Gray, R. O.; et al. (July 2006), "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 pc-The Southern Sample", The Astronomical Journal, 132 (1): 161–170, arXiv:astro-ph/0603770, Bibcode:2006AJ....132..161G, doi:10.1086/504637, S2CID 119476992
^ Evans, D. S. (June 20–24, 1966), Batten, Alan Henry; Heard, John Frederick (eds.), "The Revision of the General Catalogue of Radial Velocities", Determination of Radial Velocities and Their Applications, Proceedings from IAU Symposium No. 30, 30, University of Toronto: International Astronomical Union: 57, Bibcode:1967IAUS...30...57E
^ Cardini, D. (January 2005), "Mg II chromospheric radiative loss rates in cool active and quiet stars", Astronomy and Astrophysics, 430: 303–311, arXiv:astro-ph/0409683, Bibcode:2005A&A...430..303C, doi:10.1051/0004-6361:20041440, S2CID 12136256
^ ^a ^b Jancart, S.; et al. (October 2005), "Astrometric orbits of SB^9 stars", Astronomy and Astrophysics, 442 (1): 365–380, arXiv:astro-ph/0507695, Bibcode:2005A&A...442..365J, doi:10.1051/0004-6361:20053003, S2CID 15123997
^ Kervella, Pierre; Arenou, Frédéric; Thévenin, Frédéric (2022-01-01). "Stellar and substellar companions from Gaia EDR3. Proper-motion anomaly and resolved common proper-motion pairs". Astronomy and Astrophysics. 657: A7. arXiv:2109.10912. Bibcode:2022A&A...657A...7K. doi:10.1051/0004-6361/202142146. ISSN 0004-6361.
^ ^a ^b Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library, vol. 1 (3rd ed.), Birkhäuser, ISBN 3-540-29692-1. The radius (R_*) is given by:
${\begin{aligned}2\cdot R_{*}&={\frac {(10^{-3}\cdot 26\cdot 5.25)\ {\text{AU}}}{0.0046491\ {\text{AU}}/R_{\bigodot }}}\\&\approx 29.4\cdot R_{\bigodot }\end{aligned}}$
^ Charbonnel, C.; Lagarde, N.; Jasniewicz, G.; North, P. L.; Shetrone, M.; Krugler Hollek, J.; Smith, V. V.; Smiljanic, R.; Palacios, A.; Ottoni, G. (2020), "Lithium in red giant stars: Constraining non-standard mixing with large surveys in the Gaia era", Astronomy and Astrophysics, 633: A34, arXiv:1910.12732, Bibcode:2020A&A...633A..34C, doi:10.1051/0004-6361/201936360, S2CID 204907220
^ Pérez Martínez, M. Isabel; Schröder, K. -P.; Cuntz, M. (2011-06-01). "The basal chromospheric Mg II h+k flux of evolved stars: probing the energy dissipation of giant chromospheres". Monthly Notices of the Royal Astronomical Society. 414 (1): 418–427. arXiv:1102.4832. Bibcode:2011MNRAS.414..418P. doi:10.1111/j.1365-2966.2011.18421.x. ISSN 0035-8711.
^ Costa, J. M.; et al. (February 2002), "The tidal effects on the lithium abundance of binary systems with giant component", Astronomy and Astrophysics, 382 (3): 1016–1020, arXiv:astro-ph/0111539, Bibcode:2002A&A...382.1016C, doi:10.1051/0004-6361:20011676, S2CID 17024265
^ "alf Phe -- Spectroscopic binary", SIMBAD, Centre de Données astronomiques de Strasbourg, retrieved 2012-01-09
^ ^a ^b Kunitzsch, Paul; Smart, Tim (2006), A Dictionary of Modern star Names: A Short Guide to 254 Star Names and Their Derivations (2nd rev. ed.), Cambridge, Massachusetts: Sky Pub, ISBN 978-1-931559-44-7
^ "Star Names", International Astronomical Union, retrieved 2023-07-13
^ ^a ^b Allen, Richard Hinckley (1899), Star-names and their meanings, G. E. Stechert, p. 336
^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 27 日 Archived 2011-05-22 at the Wayback Machine
^ van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600
^ Richichi, A.; Percheron, I.; Khristoforova, M. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics, 431 (2): 773–777, Bibcode:2005A&A...431..773R, doi:10.1051/0004-6361:20042039