Zeta Phoenicis

Zeta Phoenicis
Observation data; Epoch J2000 Equinox J2000
Constellation	Phoenix
Right ascension	01h 08m 23.08s
Declination	–55° 14′ 44.7″
Apparent magnitude (V)	3.9 to 4.4
Characteristics
Spectral type	B6 V + B8 V
B−V color index	–0.12
Variable type	Algol
Astrometry
Radial velocity (Rv)	+15.4 km/s
Proper motion (μ)	RA: 20.87 mas/yr ; Dec.: 30.64 mas/yr
Parallax (π)	10.92 ± 0.39 mas
Distance	300 ± 10 ly ; (92 ± 3 pc)
Absolute magnitude (MV)	–1.49 / 0.19
Orbit
Period (P)	1.6697739 d
Semi-major axis (a)	11.022 ± 0.048 R☉
Eccentricity (e)	0.0116 ± 0.0024
Inclination (i)	89.14 ± 0.11°
Argument of periastron (ω); (secondary)	307 ± 12°
Semi-amplitude (K1); (primary)	131.4 ± 0.7 km/s
Semi-amplitude (K2); (secondary)	202.5 ± 1.3 km/s
Details
ζ Phe Aa
Mass	3.908 M☉
Radius	2.835 R☉
Luminosity	309 L☉
Surface gravity (log g)	4.1249 cgs
Temperature	14,400 K
Rotational velocity (v sin i)	85.89 km/s
ζ Phe Ab
Mass	2.536 M☉
Radius	1.885 R☉
Luminosity	66 L☉
Surface gravity (log g)	4.2917 cgs
Temperature	12,000 K
Rotational velocity (v sin i)	57.11 km/s
Other designations
	Wurren, HR 338, CD–55° 267, CPD–55° 241, HD 6882, SAO 232306, HIP 5348.
Database references
SIMBAD	data

Zeta Phoenicis (ζ Phoenicis, abbreviated Zet Phe, ζ Phe) is a multiple star system in the constellation of Phoenix. It is visible to the naked eye. Based upon parallax measurements made by the Hipparcos spacecraft, it is located some 300 light-years (92 parsecs) away.^[1]

Zeta Phoenicis A is itself an Algol-type eclipsing binary star. It consists of two B-type main sequence stars that orbit each other.^[3] The larger and brighter (Zeta Phoenicis Aa) is formally named Wurren /ˈwʊrən/.^[4] When one passes in front of one another, it blocks some of the other star's light. As a result, its apparent magnitude fluctuates between 3.9 and 4.4 with a period of 1.6697739 days (its orbital period).

The system most likely contains four stars with two other telescopic components of apparent magnitude 7.2 and 8.2 at angular separations of 0.8 and 6.4 arcseconds from the main pair.^[5] The closer (Zeta Phoenicis B) is an A-type main-sequence star^[6] with an orbital period around the main pair of about 210 years, as well as an eccentricity of about 0.35.^[7] The further (Zeta Phoenicis C) is an F-type main-sequence star with an orbital period of over 5,000 years.^[3]

Nomenclature

ζ Phoenicis (Latinised to Zeta Phoenicis) is the system's Bayer designation. The designations of the three constituents as ζ Phoenicis A, B and C, and those of A's components—ζ Phoenicis Aa and Ab—derive from the convention used by the Washington Multiplicity Catalog (WMC) for multiple star systems, and adopted by the International Astronomical Union (IAU).^[8]

The system bore the traditional name Wurren in the culture of the Wardaman people of the Northern Territory of Australia,^[9] meaning child, but in this context refers to a "Little Fish", a star adjacent to Achernar (Gawalyan = porcupine or echidna) to whom little fish provides water.^[10] In 2016, the IAU organized a Working Group on Star Names (WGSN)^[11] to catalog and standardize proper names for stars. The WGSN decided to attribute proper names to individual stars rather than entire multiple systems.^[12] It approved the name Wurren for the component Zeta Phoenicis Aa on 19 November 2017 and it is now so included in the List of IAU-approved Star Names.^[4]

In Chinese occasioned by adaptation of the European southern hemisphere constellations into the Chinese system, 水委 (Shuǐ Wěi), meaning Crooked Running Water, refers to an asterism consisting of Zeta Phoenicis, Alpha Eridani (Achernar) and Eta Phoenicis. Consequently, Zeta Phoenicis itself is known as 水委二 (Shuǐ Wěi èr, English: the Second Star of Crooked Running Water).^[13]

References

^ ^a ^b ^c ^d ^e ^f van Leeuwen, F. (2007). "HIP 5348". Hipparcos, the New Reduction. Retrieved 2009-12-14.
^ ^a ^b ^c ^d Southworth, John (2020). "Rediscussion of eclipsing binaries. Paper I. The totally-eclipsing B-type system zeta Phoenicis". The Observatory. 140: 247. arXiv:2012.05559. Bibcode:2020Obs...140..247S.
^ ^a ^b Kaler, Jim. "Zeta Phoenicis". Department of Astronomy, University of Illinois. Retrieved 2017-12-18.
^ ^a ^b "Naming Stars". IAU.org. Retrieved 16 December 2017.
^ Clausen, J. V.; Gyldenkerne, K.; Grønbech, B. (January 1976). "Four-color photometry of eclipsing binaries. IIIb: Zeta Phoenicis, analysis of light curves and determination of absolute dimensions". Astronomy and Astrophysics. 46: 205–212. Bibcode:1976A&A....46..205C.
^ Zasche, P.; Wolf, M.; Hartkopf, W. I.; Svoboda, P.; Uhlař, R.; Liakos, A.; Gazeas, K. (2009). "A Catalog of Visual Double and Multiple Stars With Eclipsing Components". The Astronomical Journal. 138 (2): 664–679. arXiv:0907.5172. Bibcode:2009AJ....138..664Z. doi:10.1088/0004-6256/138/2/664. S2CID 17089387.
^ "Sixth Catalog of Orbits of Visual Binary Stars". United States Naval Observatory. Archived from the original on 2017-08-01. Retrieved 2017-02-28.
^ Hessman, F. V.; Dhillon, V. S.; Winget, D. E.; Schreiber, M. R.; Horne, K.; Marsh, T. R.; Guenther, E.; Schwope, A.; Heber, U. (2010). "On the naming convention used for multiple star systems and extrasolar planets". arXiv:1012.0707 [astro-ph.SR].
^ "IAU Approves 86 New Star Names From Around the World" (Press release). IAU.org. 11 December 2017.
^ "IAU Working Group on Star Names (WGSN)" (Press release). IAU.org.
^ "IAU Working Group on Star Names (WGSN)". Retrieved 22 May 2016.
^ "WG Triennial Report (2015-2018) - Star Names" (PDF). p. 5. Retrieved 2018-07-14.
^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 27 日