Nu Ceti

Nu Ceti
Location of ν Ceti (circled)
Observation data
Epoch J2000.0      Equinox J2000.0
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 mas[1]
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]

  1. ^ a b c d e Cite error: The named reference van Leeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference Cousins1963 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Lutz1977 was invoked but never defined (see the help page).
  4. ^ a b c Cite error: The named reference Stephenson1969 was invoked but never defined (see the help page).
  5. ^ a b c d e f Cite error: The named reference Griffin2015 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference data was invoked but never defined (see the help page).
  7. ^ a b c d Cite error: The named reference Stock2018 was invoked but never defined (see the help page).
  8. ^ a b c Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Levato1978 was invoked but never defined (see the help page).
  11. ^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 11 日