Xi2 Ceti
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Cetus
Right ascension 02h 28m 09.55706s[1]
Declination +08° 27′ 36.2168″[1]
Apparent magnitude (V) +4.279[2]
Characteristics
Spectral type B9.5III[3] or A0III-[4]
U−B color index −0.137[5]
B−V color index −0.053±0.003[5]
Astrometry
Radial velocity (Rv)11.90±1.3[6] km/s
Proper motion (μ) RA: 23.707±0.844[1] mas/yr
Dec.: −4.787±0.778[1] mas/yr
Parallax (π)16.5681 ± 0.4608 mas[1]
Distance197 ± 5 ly
(60 ± 2 pc)
Absolute magnitude (MV)+0.45[5]
Details
Mass2.45[7] M☉
Radius2.60±0.17[8] R☉
Luminosity80.13[5] L☉
Surface gravity (log g)4.00±0.25[8] cgs
Temperature10,630±400[9] K
Metallicity [Fe/H]−0.43±0.04[5] dex
Rotational velocity (v sin i)55[7] km/s
Age127[7] Myr
Other designations
ξ2 Cet, 73 Ceti, BD+07° 388, HD 15318, HIP 11484, HR 718, SAO 110543
Database references
SIMBADdata
Exoplanet Archivedata

Xi2 Ceti, Latinized from ξ2 Ceti, is a star located in the equatorial constellation of Cetus. It is visible to the naked eye with an apparent visual magnitude of +4.3.[2] This star is located at a distance of approximately 197 light years from the Sun based on parallax, and is drifting further away with a radial velocity of 12 km/s.[6] It made its closest approach some 2.7 million years ago at a distance of around 128 light-years.[5]

Xi2 Ceti is a spectrophotometric standard star.[2] It displays a stellar classification of B9.5III,[3] which suggests it has exhausted its core hydrogen, evolved away from the main sequence, and expanded to become a giant star, although still only 127 million years old.[7] It has 2.45[7] times the mass and 2.6[8] times the radius of the Sun.

In Chinese, 天囷 (Tiān Qūn), meaning Circular Celestial Granary, refers to an asterism consisting of α Ceti, κ1 Ceti, λ Ceti, μ Ceti, ξ1 Ceti, ξ2 Ceti, ν Ceti, γ Ceti, δ Ceti, 75 Ceti, 70 Ceti, 63 Ceti and 66 Ceti. Consequently, the Chinese name for Xi2 Ceti itself is "the Sixth Star of Circular Celestial Granary", Tiān Qūn Liù.[10]

References

  1. 1 2 3 4 5 Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  2. 1 2 3 Bessell, Michael S. (1999). "Spectrophotometry: Revised Standards and Techniques". Publications of the Astronomical Society of the Pacific. 111 (765): 1426–1433. Bibcode:1999PASP..111.1426B. doi:10.1086/316454.
  3. 1 2 Cowley, A.; et al. (April 1969). "A study of the bright A stars. I. A catalogue of spectral classifications". Astronomical Journal. 74: 375–406. Bibcode:1969AJ.....74..375C. doi:10.1086/110819.
  4. ↑ Gray, R. O.; Garrison, R. F. (1987). "The Early A-Type Stars: Refined MK Classification, Confrontation with Stroemgren Photometry, and the Effects of Rotation". The Astrophysical Journal Supplement Series. 65: 581. Bibcode:1987ApJS...65..581G. doi:10.1086/191237.
  5. 1 2 3 4 5 6 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. S2CID 119257644.
  6. 1 2 Gontcharov, G. A. (November 2006). "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. S2CID 119231169.
  7. 1 2 3 4 5 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. S2CID 33401607.
  8. 1 2 3 Gordon, Kathryn D.; et al. (2019). "Angular Sizes, Radii, and Effective Temperatures of B-type Stars from Optical Interferometry with the CHARA Array". The Astrophysical Journal. 873 (1): 91. Bibcode:2019ApJ...873...91G. doi:10.3847/1538-4357/ab04b2.
  9. ↑ Zorec, J.; et al. (2009). "Fundamental parameters of B supergiants from the BCD system. I. Calibration of the (λ_1, D) parameters into Teff". Astronomy and Astrophysics. 501 (1): 297–320. arXiv:0903.5134. Bibcode:2009A&A...501..297Z. doi:10.1051/0004-6361/200811147. S2CID 14969137.
  10. ↑ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 11 日
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