Nu2 Canis Majoris

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For other star systems with this Bayer designation, see Nu Canis Majoris.
ν2 Canis Majoris
Diagram showing star positions and boundaries of the constellation of Canis Major and its surroundings
Cercle rouge 100%.svg

A star chart of the constellation of Canis Major showing the position of ν2
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Canis Major
Right ascension 06h 36m 41s
Declination −19° 15′ 21″
Apparent magnitude (V) 3.95
Spectral type K1 III
Radial velocity (Rv) 5.39 km/s
Parallax (π) 50.63 ± 0.23 mas
Distance 64.4 ± 0.3 ly
(19.75 ± 0.09 pc)
Mass 1.52 ± 0.30 M
Radius 2.3 ± 0.1 R
Luminosity 11.3 ± 0.3 L
Surface gravity (log g) 3.25 ± 0.10 cgs
Temperature 4792 ± 100 K
Metallicity [Fe/H] 0.21 ± 0.10 dex
Rotational velocity (v sin i) 1.15 km/s
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.[1]

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).[2] 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[3]

Planetary system[edit]

The Nu2 Canis Majoris system[1]
(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 Wittenmyer et al. (2011). "The Pan-Pacific Planet Search. I. A Giant Planet Orbiting 7 CMa". The Astrophysical Journal 743 (2). arXiv:1111.1007. Bibcode:2011ApJ...743..184W. doi:10.1088/0004-637X/743/2/184. 
  2. ^ (Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 16 日
  3. ^ Richard Hinckley Allen: Star Names — Their Lore and Meaning: Canis Major

External links[edit]