- Nu Ophiuchi
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Nu Ophiuchi 
Giant star Nu Ophiuchi and its brown dwarf companion.Observation data
Epoch {{{epoch}}} EquinoxConstellation Ophiuchus Right ascension 17h 59m 1.5915s Declination -09° 46′ 25.075″ Apparent magnitude (V) +3.32 Characteristics Spectral type K0III Astrometry Distance 153 ly
(46.9 pc)Details Mass 3.04[1] M☉ Radius 15.25 R☉ Luminosity 123[1] L☉ Temperature 4928[1] K Age 330[1] million years Other designations Database references SIMBAD data Nu Ophiuchi (ν Oph, ν Oph) is a Class K0, third-magnitude star in the constellation Ophiuchus. Its closest stellar neighbour is the bright binary system Tau Ophiuchi, roughly 16.9 light years away from the star. Sometimes, this star is called by the name Sinistra, meaning left side in Latin[2].
In Chinese, 天市左垣 (Tiān Shì Zuǒ Yuán), meaning Left Wall of Heavenly Market Enclosure, refers to an asterism which is represent eleven old states in China which is marking the left borderline of the enclosure, consisting of ν Ophiuchi, δ Herculis, λ Herculis, μ Herculis, ο Herculis, 112 Herculis, ζ Aquilae, θ1 Serpentis, η Serpentis, ξ Serpentis and η Ophiuchi[3]. Consequently, ν Ophiuchi itself is known as 天市左垣九 (Tiān Shì Zuǒ Yuán jiǔ, English: the Ninth Star of Left Wall of Heavenly Market Enclosure), represent the state Yan (燕)[4][5], together with ζ Capricorni in Twelve States asterism.[6]
Nu Ophiuchi is a binary star with components of magnitudes 3.3 and 6.8, separated by 2.7 arcseconds. This stellar system is located about 153 light-years (46.9 pc) from Earth.
The star has a brown dwarf companion Nu Ophiuchi b discovered in early 2004. The companion has mass of 21.9 MJ and takes 536 days to complete an orbit.[7]
The second brown dwarf companion discovered in 2010.
The Nu Ophiuchi system[7] Companion
(in order from star)Mass Semimajor axis
(AU)Orbital period
(days)Eccentricity b ≥21.9 MJ ≥1.875 536 0.13 c ≥24.5 MJ 5.88 3169 0.18 Contents
See also
References
- ^ a b c d Takeda et al.; Sato, Bun'ei; Murata, Daisuke (2008). "Stellar Parameters and Elemental Abundances of Late-G Giants". Publications of the Astronomical Society of Japan 60 (4): 781–802. arXiv:0805.2434. Bibcode 2008PASJ...60..781T.
- ^ http://www.constellationsofwords.com/stars/Sinistra.html
- ^ (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.
- ^ (Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 6 月 23 日
- ^ (Chinese) English-Chinese Glossary of Chinese Star Regions, Asterisms and Star Name, Hong Kong Space Museum. Accessed on line November 23, 2010.
- ^ (Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 4 日
- ^ a b Mitchell, D. S.; Frink, S.; Quirrenbach, A.; Fischer, D. A.; Marcy, G. W.; Butler, R. P. (2003). "Four Substellar Companions Found Around K Giant Stars". American Astronomical Society Meeting 203 203: 1234. Bibcode 2003AAS...203.1703M.
Further reading
- "HD 163917 -- Star". SIMBAD Astronomical Database. http://simbad.u-strasbg.fr/sim-id.pl?protocol=html&Ident=nu+ophiuchi&NbIdent=1&Radius=10&Radius.unit=arcmin&CooFrame=FK5&CooEpoch=2000&CooEqui=2000&output.max=all&o.catall=on&output.mesdisp=N&Bibyear1=1983&Bibyear2=2005&Frame1=FK5&Frame2=FK4&Frame3=G&Equi1=2000.0&Equi2=1950.0&Equi3=2000.0&Epoch1=2000.0&Epoch2=1950.0&Epoch3=2000.0. Retrieved 2007-01-20.
External links
Bayer α (Rasalhague) • β (Cebalrai) • γ • δ (Yed Prior) • ε (Yed Posterior) • ζ (Han) • η (Sabik) • θ • ι • κ • λ (Marfik) • μ • ν • ξ • ο • ρ • σ • τ • υ • φ • χ • ψ • ω • b • c • d • e • f • p • AFlamsteed 1 (δ, Yed Prior) • 2 (ε, Yed Posterior) • 3 (υ) • 4 (ψ) • 5 (ρ) • 7 (χ) • 8 (φ) • 9 (ω) • 10 (λ, Marfik) • 12 • 13 (ζ, Han) • 14 • 15 • 16 • 18 • 19 • 20 • 21 • 23 • 24 • 25 (ι) • 26 • 27 (κ) • 28 • 29 • 30 • 31 • 35 (η, Sabik) • 36 (A) • 37 • 38 • 39 (ο) • 40 (ξ) • 41 • 42 (θ) • 43 • 44 (b) • 45 (d) • 47 • 49 (σ) • 50 • 51 (c) • 52 • 53 (f) • 54 • 55 (α, Rasalhague) • 57 (μ) • 58 • 60 (β, Cebalrai) • 61 • 62 (γ) • 64 (ν) • 66 • 67 • 68 • 69 (τ) • 70 (p) • 71 • 72 • 73 • 74 • 24 ScoNearby Barnard's Star • Wolf 1061 • 70 (p) • 36 (A) • Gliese 644/643 (Van Biesbroeck 8) • Gliese 673 • GJ 1207List Categories:- Bayer objects
- Ophiuchus constellation
- K-type giants
- Brown dwarfs
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