Astronomy:Iota Ceti

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Short description: Star in the constellation Cetus
Iota Ceti
Observation data
Equinox J2000.0]] (ICRS)
Constellation Cetus
Right ascension  00h 19m 25.67439s[1]
Declination −08° 49′ 26.1090″[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: −14.61[1] mas/yr
Dec.: −36.668°[1] mas/yr
Parallax (π)11.6996 ± 0.1968[1] mas
Distance279 ± 5 ly
(85 ± 1 pc)
Absolute magnitude (MV)−1.2[7]
Details[8]
Mass3.7±0.1 M☉
Radius30±0.7 R☉
Luminosity377±22 L☉
Surface gravity (log g)2.1[6] cgs
Temperature4,645±73 K
Metallicity [Fe/H]−0.09[6] dex
Rotational velocity (v sin i)0.4[6] km/s
Age230±30 Myr
Other designations
ι Cet, 8 Cet, BD−09°48, FK5 9, HD 1522, HIP 1562, HR 74, SAO 128694.[9]
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.[10] 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 11.7 mas,[11] it lies around 280 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.[12] Consequently, the Chinese name for ι Ceti itself is 天倉一 (Tiān Cāng yī, English: the First Star of Square Celestial Granary.)[13]

This is an MK-standard star with a stellar classification of K1.5 III,[14] 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 3.7 times the mass of the Sun, 30 times the Sun's radius, and radiates 380 times the solar luminosity from its outer atmosphere at an effective temperature of 4,645 K.[8]

Iota Ceti forms a wide astrometric pair with a common proper motion companion,[15] a magnitude 10.40 star at an angular separation of 106.4 arcseconds along a position angle of 191° (as of 2014).[16] This companion may be a K-type star.[4]

References

  1. ↑ 1.0 1.1 1.2 1.3 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940  Gaia DR3 record for this source at VizieR.
  2. ↑ 2.0 2.1 2.2 2.3 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, doi:10.1093/mnras/172.3.667, Bibcode: 1975MNRAS.172..667J. 
  3. ↑ Luck, R. Earle (September 2015), "Abundances in the Local Region. I. G and K Giants", The Astronomical Journal 150 (3): 23, doi:10.1088/0004-6256/150/3/88, 88, Bibcode: 2015AJ....150...88L. 
  4. ↑ 4.0 4.1 4.2 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. ↑ 5.0 5.1 Eggen, O. J. (July 1993), "Evolved GK stars near the sun. I - The old disk population", Astronomical Journal 106 (1): 80–132, doi:10.1086/116622, Bibcode: 1993AJ....106...80E.  See p. 97.
  6. ↑ 6.0 6.1 6.2 6.3 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, doi:10.1088/0004-6256/135/1/209, Bibcode: 2008AJ....135..209M. 
  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, doi:10.1086/605456, Bibcode: 2009PASP..121..842R. 
  8. ↑ 8.0 8.1 Template:Ciation
  9. ↑ "iot Cet -- High proper-motion Star", SIMBAD Astronomical Database (Centre de Données astronomiques de Strasbourg), http://simbad.u-strasbg.fr/simbad/sim-id?Ident=iot+Cet, retrieved 2017-02-06. 
  10. ↑ Bakich, Michael E. (1995), The Cambridge Guide to the Constellations, Cambridge University Press, p. 116, ISBN 0521449219, https://books.google.com/books?id=tLMXiFhTnRYC&pg=PA116. 
  11. ↑ van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V. 
  12. ↑ (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.
  13. ↑ (in Chinese) 香港太空館 - 研究資源 - 亮星中英對照表 , Hong Kong Space Museum. Accessed on line November 23, 2010.
  14. ↑ Garcia, B. (June 1989), "A list of MK standard stars", Bulletin d'Information du Centre de Données Stellaires 36: 27, Bibcode: 1989BICDS..36...27G. 
  15. ↑ 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, doi:10.1051/0004-6361:20000010, Bibcode: 2001A&A...365..222G. 
  16. ↑ Mason, B. D. et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal 122 (6): 3466–3471, doi:10.1086/323920, Bibcode: 2001AJ....122.3466M. 

Coordinates: Sky map 00h 19m 26s, −08° 49′ 26″



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