Xi Phoenicis

Xi Phoenicis
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Phoenix
Right ascension 00h 41m 46.30191s[1]
Declination −56° 30′ 05.2370″[1]
Apparent magnitude (V) 5.70[2] + 9.98[3]
Characteristics
Spectral type A3 Vp(SrCr v. st; K sn)[4]
B−V color index +0.19[2]
Variable type α2 CVn[5]
Astrometry
Radial velocity (Rv)+9.8±2.9[6] km/s
Proper motion (μ) RA: +90.79[1] mas/yr
Dec.: +57.19[1] mas/yr
Parallax (π)14.92 ± 0.35[1] mas
Distance219 ± 5 ly
(67 ± 2 pc)
Absolute bolometric
magnitude (Mbol)		1.64±0.079[3]
Details[3]
ξ Phe A
Mass1.85[7] M☉
Radius2.04±0.26 R☉
Luminosity17 L☉
Surface gravity (log g)4.98±0.14[7] cgs
Temperature8,300±250 K
Rotation3.9516±0.0003 d[8]
Rotational velocity (v sin i)22.5±2 km/s
Age93[7] Myr
ξ Phe B
Mass0.81[9] M☉
Other designations
ξ Phe, CD−57° 137, HD 3980, HIP 3277, HR 183, SAO 232152, WDS J00418-5630A[10]
Database references
SIMBADdata

Xi Phoenicis, Latinized from ξ Phoenicis, is a visual binary[3] star system in the southern constellation of Phoenix. It is faintly visible to the naked eye, having an apparent visual magnitude of 5.70.[2] Based upon an annual parallax shift of 14.92 mas as measured from Earth,[1] it is located around 219 light years from the Sun. The system is moving away from the Sun with a radial velocity of about +10 km/s.[6]

As of 2007, the pair have an angular separation of 13.06 arc seconds along a position angle of 252.5°. This corresponds to a projected separation of 875.4 AU. They have a mass ratio of 0.38.[9]

The primary is a chemically peculiar Ap star with a stellar classification of A3 Vp(SrCr v. st; K sn), where the suffix notation indicating the spectrum shows very strong lines of Strontium and Chromium.[4] It has a magnetic field with a polar strength of around 7 kG. The surface abundances show inhomogeneities, with, for example, elements such as lithium and oxygen being more concentrated near the magnetic poles.[3] The star varies in luminosity with an amplitude of 0.13 magnitude at a rate matching the estimated rotation period of four days.[8] However, it does not display rapid pulsations in brightness and so is most likely not a rapidly oscillating Ap star.[11]

References

  1. 1 2 3 4 5 6 van Leeuwen, F. (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.
  2. 1 2 3 Cousins, A. W. J.; et al. (1966), "Photoelectric magnitudes and colours of southern stars, II", Royal Observatory bulletins, 121, Bibcode:1966RGOB..121....1C.
  3. 1 2 3 4 5 Nesvacil, N.; et al. (January 2012), "Multi-element Doppler imaging of the CP2 star HD 3980", Astronomy & Astrophysics, 537: 10, arXiv:1303.2703, Bibcode:2012A&A...537A.151N, doi:10.1051/0004-6361/201117097, A151.
  4. 1 2 Abt, Helmut A.; Morrell, Nidia I. (1995), "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars", Astrophysical Journal Supplement, 99: 135, Bibcode:1995ApJS...99..135A, doi:10.1086/192182.
  5. ↑ Samus, N. N.; et al. (2017), "General Catalogue of Variable Stars: Version GCVS 5.1", Astronomy Reports, 61 (1): 80−88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085.
  6. 1 2 de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, A61.
  7. 1 2 3 David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal, 804 (2): 146, arXiv:1501.03154, Bibcode:2015ApJ...804..146D, doi:10.1088/0004-637X/804/2/146.
  8. 1 2 Obbrugger, M.; et al. (April 2008), "First results on the multi-element Doppler imaging of the CP star HD3980", Contributions of the Astronomical Observatory Skalnaté Pleso, 38 (2): 347−352, Bibcode:2008CoSka..38..347O.
  9. 1 2 De Rosa, R. J.; et al. (January 2014), "The VAST Survey - III. The multiplicity of A-type stars within 75 pc", Monthly Notices of the Royal Astronomical Society, 437 (2): 1216–1240, arXiv:1311.7141, Bibcode:2014MNRAS.437.1216D, doi:10.1093/mnras/stt1932.
  10. ↑ "ksi Phe". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-09-20.
  11. ↑ Elkin, V. G.; et al. (November 2008), "A search for rapid pulsations in the magnetic cool chemically peculiar star HD3980", Monthly Notices of the Royal Astronomical Society, 390 (3): 1250−1257, arXiv:0808.2711, Bibcode:2008MNRAS.390.1250E, doi:10.1111/j.1365-2966.2008.13819.x.
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