Nu Ophiuchi
{{short description|Star in the constellation Ophiuchus}}
{{Starbox begin
| name = ν Ophiuchi
}}
{{Starbox image
| image=
{{Location mark
|image=Ophiuchus constellation map.svg|alt=|float=center|width=240
|label=|position=right
|mark=Red circle.svg|mark_width=10|mark_link=ν Oph
|x=290|y=582
}}
|caption=Location of ν Ophiuchi (circled)
}}
{{Starbox observe
| epoch = J2000
| constell = Ophiuchus
}}
{{Starbox character
| class = {{nowrap|K0 IIIa CN –1}}
| variable =
}}
{{Starbox astrometry
| radial_v = {{val|13.19|0.04}}
| prop_mo_ra = {{val|-9.48}}
| prop_mo_dec = {{val|-116.69}}
| parallax = 21.64
| p_error = 0.26
}}
{{Starbox detail
| mass = {{val|2.88|0.12}}
| gravity = {{val|2.60|0.03}}
| metal_fe = {{val|0.05|0.07}}
| age_myr = {{val|450|70}}
| luminosity = {{val|108.2|6|fmt=commas}}
| temperature = {{val|5000|63|fmt=commas}}
}}
{{Starbox catalog
| names = Sinistra, 64 Ophiuchi, BD−09 4632, FK5 673, HD 163917, HIP 88048, HR 6698, SAO 142004, 2MASS J17590160-0946249
}}
{{Starbox reference
| Simbad = 64+Oph
}}
{{Starbox end}}
Nu Ophiuchi (ν Oph, ν Ophiuchi) is a star in the equatorial constellation of Ophiuchus. The apparent visual magnitude is +3.3, 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 {{convert|150|ly|pc|abbr=off|lk=on}}.
Properties
File:Nu Ophiuchi and Companion.png companion Nu Ophiuchi b]]
Nu Ophiuchi has about three times the mass of the Sun and is roughly 450 million years old. The spectrum of the star matches a stellar classification of K0 IIIa, 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. 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, giving it the cool, orange hue of a K-type star.
Companions
This is not a binary star system in the sense of having a gravitationally-bound stellar companion. However, in November 2003, a brown dwarf companion called Nu Ophiuchi b was discovered. 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. 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. The two brown dwarfs are locked in a 1:6 orbital resonance.
{{OrbitboxPlanet begin
| period_unit=day
}}
{{OrbitboxPlanet
| exoplanet = b
| mass = 22.2-81.7
| period = 530.73{{±|0.10}}
| semimajor = 1.803
| eccentricity = 0.124{{±|0.003}}
| inclination = 16-90
}}
{{OrbitboxPlanet
| exoplanet = c
| mass = 24.7-92.0
| period = 3188.95{{±|6.26}}
| semimajor = 6.022
| eccentricity = 0.178{{±|0.006}}
| inclination = 16-90
}}
{{Orbitbox end}}
This star is following an orbit through the galaxy that carries it between {{Convert|23.4|-|29.2|kly|kpc|abbr=on|lk=on}} 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 {{Convert|100|ly|pc|abbr=on}} above the galactic plane.
Naming
This star is sometimes called by the name Sinistra, meaning left side in Latin,{{cite web|url=http://www.constellationsofwords.com/stars/Sinistra.html|title=Sinistra}} although authors like Jim Kaler recommend not using this name, and instead stick to the Bayer designation only (Nu Ophiuchi).{{cite web
|title=Nu Ophiuchi
|first=Jim|last=Kaler
|url=http://stars.astro.illinois.edu/sow/nuoph.html
|access-date=2017-01-03}}
In China, the star is part of {{lang|zh|天市左垣}} ({{lang|zh-Latn|Tiān Shì Zuǒ Yuán}}), 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.{{citation | script-title=zh:中國星座神話 | author = 陳久金 | publisher = 台灣書房出版有限公司 | date = 2005 | isbn = 978-986-7332-25-7 | language = zh }} Consequently, ν Ophiuchi itself is known as {{lang|zh|天市左垣九}} ({{lang|zh-Latn|Tiān Shì Zuǒ Yuán jiǔ}}, {{langx|en|the Ninth Star of Left Wall of Heavenly Market Enclosure}}), and together with ζ Capricorni represents the state Yan (燕){{citation | language = zh | url = http://aeea.nmns.edu.tw/2006/0606/ap060623.html | title = AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 6 月 23 日 | access-date = 2010-12-04 | archive-date = 2021-05-15 | archive-url = https://web.archive.org/web/20210515003305/http://aeea.nmns.edu.tw/2006/0606/ap060623.html | url-status = dead }}{{citation | language = zh | url = http://www.lcsd.gov.hk/CE/Museum/Space/Research/StarName/e_research_chinengstarzone_b.htm#HeavenlyMarketEnclosure | title = English-Chinese Glossary of Chinese Star Regions, Asterisms and Star Name | publisher = Hong Kong Space Museum | access-date = November 23, 2010 | url-status = dead | archive-url = https://web.archive.org/web/20080924022136/http://www.lcsd.gov.hk/CE/Museum/Space/Research/StarName/e_research_chinengstarzone_b.htm#HeavenlyMarketEnclosure | archive-date = September 24, 2008 }} in the Twelve States constellation.{{citation | language = zh | url = http://aeea.nmns.edu.tw/2006/0607/ap060704.html | title = AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 4 日 | access-date = 2010-12-04 | archive-date = 2011-05-22 | archive-url = https://web.archive.org/web/20110522123616/http://aeea.nmns.edu.tw/2006/0607/ap060704.html | url-status = dead }}
See also
References
{{Reflist|refs=
{{Cite journal |last=Jofré |first=E. |last2=Petrucci |first2=R. |last3=Saffe |first3=C. |last4=Saker |first4=L. |last5=Artur de la Villarmois |first5=E. |last6=Chavero |first6=C. |last7=Gómez |first7=M. |last8=Mauas |first8=P. J. D. |date=2015-02-01 |title=Stellar parameters and chemical abundances of 223 evolved stars with and without planets |journal=Astronomy and Astrophysics |volume=574 |page=A50 |bibcode= 2015A&A...574A..50J |doi=10.1051/0004-6361/201424474 |arxiv= 1410.6422 |s2cid=53666931 |issn=0004-6361}} [https://vizier.cds.unistra.fr/viz-bin/VizieR?-source=J/A%2BA/574/A50&Name=HD%20163917 Nu Ophiuchi's database entry] at VizieR.
{{cite simbad | title=nu. Oph | accessdate=2012-02-19 }}
{{citation | title=Four Substellar Companions Found Around K Giant Stars | publisher = American Astronomical Society | bibcode=2003AAS...203.1703M | last1=Mitchell | first1=D. S. | last2=Frink | first2=S. | last3=Quirrenbach | first3=A. | last4=Fischer | first4=D. A. | last5=Marcy | first5=G. W. | last6=Butler | first6=R. P. | volume=203 | year=2003 | pages=1234 | journal=American Astronomical Society Meeting 203 }}
{{cite journal | last1=Eggleton | first1=P. P. | last2=Tokovinin | first2=A. A. | title=A catalogue of multiplicity among bright stellar systems | journal=Monthly Notices of the Royal Astronomical Society | volume=389 | issue=2 | pages=869–879 |date=September 2008 | doi=10.1111/j.1365-2966.2008.13596.x | doi-access=free | bibcode=2008MNRAS.389..869E |arxiv = 0806.2878 | s2cid=14878976 }}
{{citation | title=The Colour of Stars | date=December 21, 2004 | work=Australia Telescope, Outreach and Education | publisher=Commonwealth Scientific and Industrial Research Organisation | url=http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html | access-date=2012-01-16 | archive-url=https://web.archive.org/web/20131203222826/http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html | archive-date=December 3, 2013 | url-status=dead }}
{{citation | first=F. | last=van Leeuwen |date=November 2007 | title=Validation of the new Hipparcos reduction | journal=Astronomy and Astrophysics | volume=474 | issue=2 | pages=653–664 | bibcode=2007A&A...474..653V | doi=10.1051/0004-6361:20078357 |arxiv = 0708.1752 | s2cid=18759600 }} [https://vizier.cds.unistra.fr/viz-bin/VizieR?-source=I/311&HIP=88048 Nu Ophiuchi's database entry] at VizieR.
}}
{{Stars of Ophiuchus}}
{{DEFAULTSORT:Nu Ophiuchi}}
Category:Planetary systems with two confirmed planets