Nu Ophiuchi

From Wikipedia, the free encyclopedia

Template:Short description

ν Ophiuchi
Observation data
Epoch J2000      Equinox J2000
Constellation Ophiuchus
Right ascension Template:RA[1]
Declination Template:DEC[1]
Apparent magnitude (V) +3.332[2]
Characteristics
Spectral type K0 IIIa CN –1[3]
U−B color index +0.873[2]
B−V color index +0.999[2]
Astrometry
Radial velocity (Rv)13.19±0.04[4] km/s
Proper motion (μ) RA: −9.48 mas/yr[1]
Dec.: −116.69 mas/yr[1]
Parallax (π)21.64±0.26 mas[1]
DistanceTemplate:Rnd ± Template:Rnd ly
(Template:Rnd ± Template:Rnd pc)
Absolute magnitude (MV)–0.19[5]
Details
Mass2.88±0.12[4] M☉
Radius13.85±0.17[6] R☉
Luminosity108.2±6[6] L☉
Surface gravity (log g)2.60±0.03[4] cgs
Temperature5,000±63[6] K
Metallicity [Fe/H]0.05±0.07[4] dex
Rotational velocity (v sin i)2.1[7] km/s
Age450±70[4] Myr
Other designations
Template:Odlist[8]
Database references
SIMBADdata
Exoplanet Archivedata

Nu Ophiuchi (ν Oph, ν Ophiuchi) is a star in the equatorial constellation of Ophiuchus. The apparent visual magnitude is +3.3,[2] making it one of the brighter members of this constellation. Based upon parallax measurements made by the Hipparcos satellite, this star is located at a distance of about 150 light-years (46 parsecs).[1]

Nomenclature

Nu Ophiuchi (Latinized from ν Ophiuchi, abbreviated ν Oph) is the star's Bayer designation. This star is sometimes called by the name Sinistra, meaning left side in Latin, usually in an astrological context.[9][10] Astronomer Jim Kaler recommended not using this name, and instead sticks to the Bayer designation only.[11]

In Chinese astronomy, the star is part of Script error: No such module "Lang". (Script error: No such module "Lang".), meaning Left Wall of Heavenly Market Enclosure. The stars in this group include ν Ophiuchi, δ Herculis, λ Herculis, μ Herculis, ο Herculis, 112 Herculis, ζ Aquilae, θ1 Serpentis, η Serpentis, ξ Serpentis and η Ophiuchi.[12] Consequently, ν Ophiuchi itself is known as Script error: No such module "Lang". (Script error: No such module "Lang"., Template:Langx), and represents the state Yan (燕),[13][14] together with ζ Capricorni in the Twelve States constellation.[15]

Properties

File:Nu Ophiuchi and Companion.png
Artist's impression of Nu Ophiuchi and its brown dwarf companion Nu Ophiuchi b

Nu Ophiuchi has about three times the mass of the Sun and is roughly 450 million years old.[4] The spectrum of the star matches a stellar classification of K0 IIIa,[3] indicating it is a giant star that has exhausted the supply of hydrogen at its core and evolved away from the main sequence of stars. Unusually, it displays an anomalously low abundance of cyanogen for a star of its type.[3] The star's outer envelope has expanded to around 14 times the Sun's radius and now radiates with a luminosity 108 times that of the Sun. This energy is emitted from its outer envelope at an effective temperature of 5,000 K,[6] giving it the cool, orange hue of a K-type star.[16]

This star is following an orbit through the galaxy that carries it between 23.4–29.2 kly (7.2–9.0 kpc) from the Galactic Center. As a probable member of the Milky Way's thin disk population, it has a low orbital inclination that carries it no more than about 100 ly (31 pc) above the galactic plane.[17]

Companions

This is not a binary star system in the sense of having a gravitationally-bound stellar companion.[18] However, in November 2003, a brown dwarf companion called Nu Ophiuchi b was discovered by the radial velocity method. This sub-stellar companion has at least 21.9 times the mass of Jupiter and takes 536 days (1.47 years) to complete an orbit.[19] A second brown dwarf companion was discovered in 2010, orbiting further from the star with a period of 3,169 days (8.68 years). These were confirmed in 2012.[20] The two brown dwarfs are locked in a 6:1 orbital resonance, implying that they likely formed like planets from a circumstellar disk around the star.[21]

The Nu Ophiuchi planetary system[21]
Companion
(in order from star) 		Mass Semimajor axis
(AU) 		Orbital period
(days) 		Eccentricity Inclination
(°) 		Radius
b 22.2-81.7 MJ 1.803 530.73±0.10 0.124±0.003 16-90 —
c 24.7-92.0 MJ 6.022 3188.95±6.26 0.178±0.006 16-90 —

See also

References

Page Template:Reflist/styles.css has no content.

  1. ^ a b c d e Page Module:Citation/CS1/styles.css has no content.van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600 Nu Ophiuchi's database entry at VizieR.
  2. ^ a b c d Page Module:Citation/CS1/styles.css has no content.Gutierrez-Moreno, Adelina; et al. (1966), "A System of photometric standards", Publications of the Department of Astronomy University of Chile, 1, Publicaciones Universidad de Chile, Department de Astronomy: 1–17, Bibcode:1966PDAUC...1....1G
  3. ^ a b c Page Module:Citation/CS1/styles.css has no content.Morgan, W. W.; Keenan, P. C. (1973), "Spectral Classification", Annual Review of Astronomy and Astrophysics, 11 (1): 29, Bibcode:1973ARA&A..11...29M, doi:10.1146/annurev.aa.11.090173.000333
  4. ^ a b c d e f Page Module:Citation/CS1/styles.css has no content.Jofré, E.; Petrucci, R.; Saffe, C.; Saker, L.; Artur de la Villarmois, E.; Chavero, C.; Gómez, M.; Mauas, P. J. D. (2015-02-01), "Stellar parameters and chemical abundances of 223 evolved stars with and without planets", Astronomy and Astrophysics, 574: A50, arXiv:1410.6422, Bibcode:2015A&A...574A..50J, doi:10.1051/0004-6361/201424474, ISSN 0004-6361, S2CID 53666931. Nu Ophiuchi's database entry at VizieR.
  5. ^ Page Module:Citation/CS1/styles.css has no content.Takeda, Yoichi; Sato, Bun'ei; Murata, Daisuke (August 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, doi:10.1093/pasj/60.4.781
  6. ^ a b c d Page Module:Citation/CS1/styles.css has no content.Baines, Ellyn K.; Armstrong, J. Thomas; Schmitt, Henrique R.; Zavala, R. T.; Benson, James A.; Hutter, Donald J.; Tycner, Christopher; Van Belle, Gerard T. (2018), "Fundamental Parameters of 87 Stars from the Navy Precision Optical Interferometer", The Astronomical Journal, 155 (1): 30, arXiv:1712.08109, Bibcode:2018AJ....155...30B, doi:10.3847/1538-3881/aa9d8b, S2CID 119427037.
  7. ^ Page Module:Citation/CS1/styles.css has no content.Massarotti, Alessandro; et al. (January 2008), "Rotational and Radial Velocities for a Sample of 761 HIPPARCOS Giants and the Role of Binarity", The Astronomical Journal, 135 (1): 209–231, Bibcode:2008AJ....135..209M, doi:10.1088/0004-6256/135/1/209, S2CID 121883397
  8. ^ Page Module:Citation/CS1/styles.css has no content."nu. Oph". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2012-02-19. {{cite web}}: Invalid |mode=Script error: No such module "Citation mode". (help)
  9. ^ Page Module:Citation/CS1/styles.css has no content."Sinistra".
  10. ^ Page Module:Citation/CS1/styles.css has no content.Robson, Vivian E. (1923). The Fixed Stars And Constellations In Astrology. p. 112.
  11. ^ Page Module:Citation/CS1/styles.css has no content.Kaler, Jim. "Nu Ophiuchi". Retrieved 2017-01-03.
  12. ^ Page Module:Citation/CS1/styles.css has no content.陳久金 (2005), 中國星座神話 (in 中文), 台灣書房出版有限公司, ISBN 978-986-7332-25-7
  13. ^ Page Module:Citation/CS1/styles.css has no content.AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 6 月 23 日 (in 中文), archived from the original on 2021-05-15, retrieved 2010-12-04
  14. ^ Page Module:Citation/CS1/styles.css has no content.English-Chinese Glossary of Chinese Star Regions, Asterisms and Star Name (in 中文), Hong Kong Space Museum, archived from the original on September 24, 2008, retrieved November 23, 2010
  15. ^ Page Module:Citation/CS1/styles.css has no content.AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 4 日 (in 中文), archived from the original on 2011-05-22, retrieved 2010-12-04
  16. ^ Page Module:Citation/CS1/styles.css has no content."The Colour of Stars", Australia Telescope, Outreach and Education, Commonwealth Scientific and Industrial Research Organisation, December 21, 2004, archived from the original on December 3, 2013, retrieved 2012-01-16
  17. ^ Page Module:Citation/CS1/styles.css has no content.Soubiran, C.; et al. (2008), "Vertical distribution of Galactic disk stars. IV. AMR and AVR from clump giants", Astronomy and Astrophysics, 480 (1): 91–101, arXiv:0712.1370, Bibcode:2008A&A...480...91S, doi:10.1051/0004-6361:20078788, S2CID 16602121
  18. ^ Page Module:Citation/CS1/styles.css has no content.Eggleton, P. P.; Tokovinin, A. A. (September 2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869–879. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. S2CID 14878976.
  19. ^ Page Module:Citation/CS1/styles.css has no content.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, American Astronomical Society: 1234, Bibcode:2003AAS...203.1703M
  20. ^ Page Module:Citation/CS1/styles.css has no content.Sato, Bun'ei; et al. (2012). "Substellar Companions to Seven Evolved Intermediate-Mass Stars". Publications of the Astronomical Society of Japan. 64 (6). 135. arXiv:1207.3141. Bibcode:2012PASJ...64..135S. doi:10.1093/pasj/64.6.135.
  21. ^ a b Page Module:Citation/CS1/styles.css has no content.Quirrenbach, Andreas; Trifonov, Trifon; Lee, Man Hoi; Reffert, Sabine (2019), "Precise radial velocities of giant stars. XI. Two brown dwarfs in 6:1 mean motion resonance around the K giant star ν Ophiuchi", Astronomy & Astrophysics, 624: A18, arXiv:1904.03557, Bibcode:2019A&A...624A..18Q, doi:10.1051/0004-6361/201834423, S2CID 102351148

Template:Stars of Ophiuchus

Retrieved from "https://cosmopedia.co/index.php?title=Nu_Ophiuchi&oldid=3391431"