Nu2 Canis Majoris

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For other stars with this Bayer designation, see ν Canis Majoris.
ν2 Canis Majoris
Canis Major constellation map.svg
link=ν2 CMa

Location of ν2 Canis Majoris (circled)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Canis Major
Right ascension 06h 36m 41.038s[1]
Declination −19° 15′ 21.17″[1]
Apparent magnitude (V) 3.96[2]
Spectral type K1 III[2]
Radial velocity (Rv) 5.39 km/s
Proper motion (μ) RA: 62.57 ± 0.15[1] mas/yr
Dec.: −69.97 ± 0.16[1] mas/yr
Parallax (π) 50.63 ± 0.23[1] mas
Distance 64.4 ± 0.3 ly
(19.75 ± 0.09 pc)
Absolute magnitude (MV) −0.05[2]
Mass 1.3±0.1 M
Radius 4.9±0.1 R
Luminosity 11.3±0.1 L
Surface gravity (log g) 3.18±0.03 cgs
Temperature 4,790±27 K
Metallicity [Fe/H] 0.21±0.10 dex
Rotational velocity (v sin i) 1.15[citation needed] km/s
Age 4.6±0.7 Gyr
Other designations
7 Canis Majoris, HR 2429, HD 47205, Gl 239.1, BD −19° 1502, FK5 2510, HIP 31592, SAO 151702, GC 8624
Database references

Nu2 Canis Majoris2 CMa, ν2 Canis Majoris) is a star in the constellation Canis Major. It is an evolved K-type giant approximately 65 light years away, seen below Sirius. Around 1.5 times as massive as the Sun, it has expanded to around 2.3 times the Sun's diameter and 11 times its luminosity. In 2011, it was discovered to have a planet.[4]

Chinese name[edit]

In Chinese astronomy, ν2 Canis Majoris is called 野雞, Pinyin: Yějī, meaning Wild Cockerel, because this star is marking itself and stand alone in Wild Cockerel asterism, Well mansion (see : Chinese constellation).[5] 野雞 (Yějī), westernized into Ya Ke. According to R.H. Allen opinion, the name Ya Ke is asterism consisting ο1 Canis Majoris and π Canis Majoris, with other small stars in the body of the Dog[6]

Planetary system[edit]

The Nu2 Canis Majoris planetary system[4]
(in order from star)
Mass Semimajor axis
Orbital period
Eccentricity Inclination Radius
b ≥2.6 ± 0.6 MJ 1.9 ± 0.1 763 ± 17 0.14 ± 0.06


  1. ^ a b c d e van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752Freely accessible. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.  Vizier catalog entry
  2. ^ a b c Setiawan, J.; et al. (July 2004), "Precise radial velocity measurements of G and K giants. Multiple systems and variability trend along the Red Giant Branch", Astronomy and Astrophysics, 421: 241−254, Bibcode:2004A&A...421..241S, doi:10.1051/0004-6361:20041042-1. 
  3. ^ Bonfanti, A.; et al. (2015). "Revising the ages of planet-hosting stars". Astronomy and Astrophysics. 575. A18. arXiv:1411.4302Freely accessible. Bibcode:2015A&A...575A..18B. doi:10.1051/0004-6361/201424951. 
  4. ^ a b Wittenmyer; et al. (2011). "The Pan-Pacific Planet Search. I. A Giant Planet Orbiting 7 CMa". The Astrophysical Journal. 743 (2). arXiv:1111.1007Freely accessible. Bibcode:2011ApJ...743..184W. doi:10.1088/0004-637X/743/2/184. 
  5. ^ (Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 16 日
  6. ^ Richard Hinckley Allen: Star Names — Their Lore and Meaning: Canis Major

External links[edit]