Iota Ceti
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Cetus
Right ascension 00h 19m 25.67416s[1]
Declination −08° 49′ 26.1111″[1]
Apparent magnitude (V) 3.562[2]
Characteristics
Spectral type K1.5 III[3] or K1 II + (K)[4]
U−B color index +1.278[2]
B−V color index +1.212[2]
Variable type Suspected[5]
Astrometry
Radial velocity (Rv)+19.35±0.17[6] km/s
Proper motion (μ) RA: −15.15[1] mas/yr
Dec.: −37.11[1] mas/yr
Parallax (π)11.88 ± 0.18 mas[1]
Distance275 ± 4 ly
(84 ± 1 pc)
Absolute magnitude (MV)−1.2[7]
Details[6]
Mass2.78[3] M☉
Radius34 R☉
Luminosity398 L☉
Surface gravity (log g)2.1 cgs
Temperature4,446±18 K
Metallicity [Fe/H]−0.09 dex
Rotational velocity (v sin i)0.4 km/s
Age2.23[3] Gyr
Other designations
ι Cet, 8 Cet, BD−09° 48, FK5 9, HD 1522, HIP 1562, HR 74, SAO 128694.[8]
Database references
SIMBADdata

Iota Ceti (ι Cet, ι Ceti) is the Bayer designation for a star system in the equatorial constellation of Cetus. It has the traditional name Deneb Kaitos Shemali.[9] The name was from the Arabic word ذنب قيطس الشمالي - dhanab qayṭas al-shamālī, meaning the northern tail of the sea monster. it is visible to the naked eye with an apparent visual magnitude of 3.562.[2] Based upon an annual parallax shift of 11.88 mas,[1] it lies around 275 light years from the Sun.

In Chinese, 天倉 (Tiān Cāng), meaning Square Celestial Granary, refers to an asterism consisting of ι Ceti, η Ceti, θ Ceti, ζ Ceti, τ Ceti and 57 Ceti.[10] Consequently, the Chinese name for ι Ceti itself is 天倉一 (Tiān Cāng yī, English: the First Star of Square Celestial Granary.)[11]

This is an MK-standard star with a stellar classification of K1.5 III,[12] indicating that it is an evolved K-type giant star. However, Houk and Swift (1999) list a classification of K1 II,[4] which would indicate this is a bright giant. It is a suspected variable with a visual amplitude of around 0.05 magnitude.[5] The star has about 2.8[3] times the mass of the Sun, 34 times the Sun's radius, and radiates 398 times the solar luminosity from its outer atmosphere at an effective temperature of 4,446 K.[6]

Iota Ceti forms a wide astrometric pair with a common proper motion companion,[13] a magnitude 10.40 star at an angular separation of 106.4 arcseconds along a position angle of 191° (as of 2014).[14] This companion may be a K-type star.[4]

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, S2CID 18759600.
  2. 1 2 3 4 Jennens, P. A.; Helfer, H. L. (September 1975), "A new photometric metal abundance and luminosity calibration for field G and K giants", Monthly Notices of the Royal Astronomical Society, 172 (3): 667–679, Bibcode:1975MNRAS.172..667J, doi:10.1093/mnras/172.3.667.
  3. 1 2 3 4 Luck, R. Earle (September 2015), "Abundances in the Local Region. I. G and K Giants", The Astronomical Journal, 150 (3): 23, arXiv:1507.01466, Bibcode:2015AJ....150...88L, doi:10.1088/0004-6256/150/3/88, S2CID 118505114, 88.
  4. 1 2 3 Houk, N.; Swift, C. (1999), "Michigan catalogue of two-dimensional spectral types for the HD Stars", Michigan Spectral Survey, Ann Arbor, Michigan: Department of Astronomy, University of Michigan, 5, Bibcode:1999MSS...C05....0H.
  5. 1 2 Eggen, O. J. (July 1993), "Evolved GK stars near the sun. I - The old disk population", Astronomical Journal, 106 (1): 80–132, Bibcode:1993AJ....106...80E, doi:10.1086/116622. See p. 97.
  6. 1 2 3 Massarotti, Alessandro; et al. (January 2008), "Rotational and radial velocities for a sample of 761 HIPPARCOS giants and the role of binarity", The Astronomical Journal, 135 (1): 209–231, Bibcode:2008AJ....135..209M, doi:10.1088/0004-6256/135/1/209, S2CID 121883397.
  7. ↑ Ryon, Jenna; et al. (August 2009), "Comparing the Ca ii H and K Emission Lines in Red Giant Stars", Publications of the Astronomical Society of the Pacific, 121 (882): 842, arXiv:0907.3346, Bibcode:2009PASP..121..842R, doi:10.1086/605456, S2CID 17821279.
  8. ↑ "iot Cet -- High proper-motion Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2017-02-06.
  9. ↑ Bakich, Michael E. (1995), The Cambridge Guide to the Constellations, Cambridge University Press, p. 116, ISBN 0521449219.
  10. ↑ (in Chinese) 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, ISBN 978-986-7332-25-7.
  11. ↑ (in Chinese) 香港太空館 - 研究資源 - 亮星中英對照表 Archived 2009-09-29 at the Wayback Machine, Hong Kong Space Museum. Accessed on line November 23, 2010.
  12. ↑ Garcia, B. (June 1989), "A list of MK standard stars", Bulletin d'Information du Centre de Données Stellaires, 36: 27, Bibcode:1989BICDS..36...27G.
  13. ↑ Gontcharov, G. A.; et al. (2001), "The proper motions of fundamental stars. I. 1535 stars from the Basic FK5", Astronomy and Astrophysics, 365 (2): 222, Bibcode:2001A&A...365..222G, doi:10.1051/0004-6361:20000010.
  14. ↑ Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122 (6): 3466–3471, Bibcode:2001AJ....122.3466M, doi:10.1086/323920.
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