Astronomy:Nu Ceti

From HandWiki
Short description: Binary star system in the constellation Cetus
Nu Ceti
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
B
Mass1.124[9] M☉
Radius1.075[9] R☉
Luminosity1.421[9] L☉
Surface gravity (log g)4.36[9] cgs
Temperature6,077[9] K
Age1.3[9] Gyr
Other designations
Struve 281, 78 Ceti, BD+04°418, HD 16161, HIP 12093, HR 754, SAO 110635, WDS J02359+0536[10]
Database references
SIMBADdata

Nu Ceti is a binary star[5] system in the equatorial constellation of Cetus. Its name is a Bayer designation that is Latinized from ν Ceti, and abbreviated ν Ceti or ν Cet. This system is visible to the naked eye as a faint point of light with a combined apparent visual magnitude of 4.86.[2] It is located approximately 340 light years distant from the Sun, based on parallax measurements, 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.[11]

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.[12]

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 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, 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, Bibcode: 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, Bibcode: 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, Bibcode: 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, Bibcode: 2015Obs...135...15G. 
  6. ↑ Nu Ceti, http://www.astrostudio.org/xhip.php?hip=12093, retrieved 2013-02-26. 
  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, Bibcode: 2018A&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. Bibcode: 2018A&A...616A...1G.  18118925129052544 Gaia DR2 record for this source at VizieR.
  9. ↑ 9.0 9.1 9.2 9.3 9.4 9.5 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.
  10. ↑ "nu. Cet". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=nu.+Cet. 
  11. ↑ 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, Bibcode: 1978PASP...90..429L. 
  12. ↑ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 11 日