Nu Draconis

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ν12 Draconis
Observation data
Epoch J2000      Equinox J2000
Constellation Draco
ν1 Dra
Right ascension 17h 32m 10.56856s[1]
Declination +55° 11′ 03.2739″[1]
Apparent magnitude (V) +4.88[2]
ν2 Dra
Right ascension 17h 32m 16.02464s[1]
Declination +55° 10′ 22.6504″[1]
Apparent magnitude (V) +4.88[2]
Spectral type A6 V[3] + A4m[4]
U−B color index +0.03/+0.04[2]
B−V color index +0.26/+0.27[2]
ν1 Dra
Radial velocity (Rv) –15.2[5] km/s
Proper motion (μ) RA: +147.39[1] mas/yr
Dec.: +54.31[1] mas/yr
Parallax (π) 33.06 ± 0.15[1] mas
Distance 98.7 ± 0.4 ly
(30.2 ± 0.1 pc)
ν2 Dra
Radial velocity (Rv) –16.0[5] km/s
Proper motion (μ) RA: +142.65[1] mas/yr
Dec.: +62.43[1] mas/yr
Parallax (π) 32.80 ± 0.18[1] mas
Distance 99.4 ± 0.5 ly
(30.5 ± 0.2 pc)
ν1 Dra
Rotational velocity (v sin i) 86[6] km/s
ν2 Dra
Rotational velocity (v sin i) 68[6] km/s
Other designations
ν Draconis, ν Dra, Kuma
ν1 Dra: 24 Dra, BD+55 1944, FK5 655, HD 159541, HIP 85819, HR 6554, SAO 30447.[3]
ν2 Dra: 25 Dra, BD+55 1945, FK5 657, HD 159560, HIP 85829, HR 6555, SAO 30450.[4]
Database references
ν Dra A
ν Dra B

Nu Draconis (also known as ν Dra, ν Draconis, or Kuma) is a double star in the constellation Draco. The respective components are designated ν1 Draconis and ν2 Draconis. The second component is a spectroscopic binary star system.[4]

This star, along with β Dra (Rastaban), γ Dra (Eltanin), μ Dra (Erakis) and ξ Dra (Grumium) were Al ʽAwāïd, "the Mother Camels", which was later known as the Quinque Dromedarii.[7]

In Chinese, 天棓 (Tiān Bàng), meaning Celestial Flail, refers to an asterism consisting of ν Draconis, ξ Draconis, β Draconis, γ Draconis and ι Herculis.[8] Consequently, ν Draconis itself is known as 天棓二 (Tiān Bàng èr, English: the Second Star of Celestial Flail.)[9]


  1. ^ a b c d e f g h i j van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, Bibcode:2007A&A...474..653V, arXiv:0708.1752Freely accessible, doi:10.1051/0004-6361:20078357 
  2. ^ a b c d Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99), Bibcode:1966CoLPL...4...99J 
  3. ^ a b "24 Dra -- Star in double system", SIMBAD Astronomical Object Database, Centre de Données astronomiques de Strasbourg, retrieved 2010-06-04 
  4. ^ a b c "25 Dra -- Spectroscopic binary", SIMBAD Astronomical Object Database, Centre de Données astronomiques de Strasbourg, retrieved 2010-06-04 
  5. ^ a b Wilson, Ralph Elmer (1953), General Catalogue of Stellar Radial Velocities, Washington: Carnegie Institution of Washington, Bibcode:1953GCRV..C......0W 
  6. ^ a b Royer, F.; et al. (October 2002), "Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i", Astronomy and Astrophysics, 393: 897–911, Bibcode:2002A&A...393..897R, arXiv:astro-ph/0205255Freely accessible, doi:10.1051/0004-6361:20020943 
  7. ^ Allen, R. H. (1963), Star Names: Their Lore and Meaning (Reprint ed.), New York, NY: Dover Publications Inc, p. 207, ISBN 0-486-21079-0, retrieved 2010-12-12 
  8. ^ (in Chinese) 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, ISBN 978-986-7332-25-7.
  9. ^ (in Chinese) 香港太空館 - 研究資源 - 亮星中英對照表, Hong Kong Space Museum. Accessed on line November 23, 2010.

External links[edit]

  • Kaler, James. Kuma