Astronomy:Nu Ceti

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Short description: Binary star system in the constellation Cetus
Nu Ceti
Cetus constellation map.svg
Red circle.svg
Location of ν Ceti (circled)
Observation data
Equinox J2000.0]] (ICRS)
Constellation Cetus
Right ascension  02h 35m 52.473s[1]
Declination +05° 35′ 35.69″[1]
Apparent magnitude (V) 4.86[2] + 9.08[3] (visual companion)
Characteristics
Spectral type G8III + F7V (visual companion)[4]
U−B color index 0.52[2]
B−V color index 0.88[2]
Astrometry
Radial velocity (Rv)4.81±0.02[5] km/s
Proper motion (μ) RA: −26.51±0.25[1] mas/yr
Dec.: −22.32±0.22[1] mas/yr
Parallax (π)9.59 ± 0.23[1] mas
Distance340 ± 8 ly
(104 ± 3 pc)
Absolute magnitude (MV)−0.415[6]
Orbit[5]
Primaryν Ceti A
Period (P)714.48±0.15 days
Eccentricity (e)0.274±0.005
Periastron epoch (T)53364.9±1.9
Argument of periastron (ω)
(secondary)
119.5±1.1°
Semi-amplitude (K1)
(primary)
5.09±0.03 km/s
Details
Aa
Mass2.65[7] M
Radius15.87+1.06
−2.19
[8] R
Luminosity161.4±7.9[8] L
Surface gravity (log g)2.56[7] cgs
Temperature5,164+417
−164
[8] K
Age537[7] Myr
Other designations
Struve 281, 78 Ceti, BD+04°418, HD 16161, HIP 12093, HR 754, SAO 110635, WDS J02359+0536[9]
Database references
SIMBADdata

ν Ceti, Latinized as Nu Ceti, is a binary star[5] system in the equatorial constellation of Cetus. It is visible to the naked eye as a faint point of light with a combined apparent visual magnitude of 4.86.[2] The system is located approximately 340 light years distant from the Sun, based on parallax, and is drifting further away with a radial velocity of 4.8 km/s.[5] Nu Ceti is believed to be part of the Ursa Major stream of co-moving stars.[10]

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 ν Ceti itself is "the Seventh Star of Circular Celestial Granary", Tiān Qūn Qī.[11]

The primary, designated component A, forms a single-lined spectroscopic binary with an orbital period of 1.96 years and an eccentricity of 0.27.[5] The visible component is a G-type giant star, currently on the horizontal branch,[7] with a stellar classification of G8III.[4] In addition to the spectroscopic companion there is a visual companion star which shares a common proper motion with Nu Ceti A, designated component B; an F-type main-sequence star with a class of F7V[4] and a 9.08 apparent visual magnitude located 8.0 arcsec away. It was discovered by Struve.[5][3]

References

  1. 1.0 1.1 1.2 1.3 1.4 van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. doi:10.1051/0004-6361:20078357. Bibcode2007A&A...474..653V. http://www.aanda.org/articles/aa/full/2007/41/aa8357-07/aa8357-07.html.  Vizier catalog entry
  2. 2.0 2.1 2.2 2.3 Cousins, A. W. J. (1963). "Photometric Data for Stars in the Equatorial Zone (Third List)". Monthly Notes of the Astronomical Society of Southern Africa 22: 12–17. Bibcode1963MNSSA..22...12C. http://articles.adsabs.harvard.edu/full/1963MNSSA..22...12C. 
  3. 3.0 3.1 Lutz, T. E.; Lutz, J. H. (1977). "Spectral classification and UBV photometry of bright visual double stars". The Astronomical Journal 82: 431–434. doi:10.1086/112066. Bibcode1977AJ.....82..431L. http://articles.adsabs.harvard.edu/full/1977AJ.....82..431L. 
  4. 4.0 4.1 4.2 Stephenson, C. B.; Sanwal, N. B. (1969). "The masses of stars above the main sequence". The Astronomical Journal 74: 689–704. doi:10.1086/110845. Bibcode1969AJ.....74..689S. http://articles.adsabs.harvard.edu/full/1969AJ.....74..689S. 
  5. 5.0 5.1 5.2 5.3 5.4 5.5 Griffin, R. F. (2015). "Spectroscopic binary orbits from photoelectric radial velocities. Paper 240: BD+59 224, HD 9592, HD 10171, HD 11738, and nu Ceti". The Observatory 135: 15–41. Bibcode2015Obs...135...15G. http://articles.adsabs.harvard.edu/full/2015Obs...135...15G. 
  6. "Nu Ceti". http://www.astrostudio.org/xhip.php?hip=12093. 
  7. 7.0 7.1 7.2 7.3 Stock, Stephan et al. (August 2018), "Precise radial velocities of giant stars. X. Bayesian stellar parameters and evolutionary stages for 372 giant stars from the Lick planet search", Astronomy & Astrophysics 616: 15, doi:10.1051/0004-6361/201833111, A33, Bibcode2018A&A...616A..33S. 
  8. 8.0 8.1 8.2 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  9. "nu. Cet". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=nu.+Cet. 
  10. Levato, H.; Abt, H. A. (August 1978), "Spectral types in the Ursa Major stream", Publications of the Astronomical Society of the Pacific 90: 429−433, doi:10.1086/130352, Bibcode1978PASP...90..429L. 
  11. (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 11 日

External links