{{Short description|Binary star system in the constellation Boötes}} {{Starbox begin}} {{Starbox observe | epoch = J2000 | constell = [[Boötes]]<ref name=Anderson_Francis_2012/> | ra = {{RA|13|39|34.61613}}<ref name="vanLeeuwen2007"/> | dec = {{DEC|+10|44|46.5827}}<ref name="vanLeeuwen2007"/> | appmag_v = 5.57<ref name=Anderson_Francis_2012/> {{nowrap|(6.35 + 6.47)&zwj;<ref name=aa546_A69_5/>}} }} {{Starbox character | type = [[Main sequence]]<ref name=Schröder_et_al_2009/><ref name=Zorec_Royer_2012/> | class = F0V<ref name=aaa463_2_671/> | b-v = +0.33<ref name="MERMILLIOD"/> | u-b = +0.045<ref name="MERMILLIOD"/> | variable = }} {{Starbox astrometry | radial_v = {{val|−25.9|1.9}}<ref name=aa475_519/> | prop_mo_ra = −114.96<ref name="vanLeeuwen2007"/> | prop_mo_dec = −11.74<ref name="vanLeeuwen2007"/> | parallax = 16.67 | p_error = 0.58 | parallax_footnote = <ref name="vanLeeuwen2007"/> | absmag_v = +2.40<ref name=Reiners2006/> }} {{Starbox orbit | reference=<ref name=ORB6/> | period = {{val|22.460|0.019}} | axis = {{val|0.19983|0.00055}} | inclination = {{val|43.50|0.40}} | node = {{val|34.58|0.52}} | periastron = [[Besselian year|B]] {{val|1929.850|0.024}} | eccentricity = {{val|0.5450|0.0022}} | periarg = {{val|359.93|0.79}} }} {{Starbox detail | component1 = A | mass = 1.59<ref name=msc/> | radius = | luminosity = | temperature = | metal_fe = | gravity = | rotational_velocity = | age_myr = | component2 = B | mass2 = 1.55<ref name=msc/> }} {{Starbox catalog | names = {{odlist | ADS=8987 | BD=+11°2589 | HD=118889 | HIP=66640 | HR=5138 | SAO=100654 | WDS=13396+1045 | DC=BU 612 }} }} {{Starbox reference | Simbad = HD+118889 }} {{Starbox end}}

'''HD 118889''' is a [[binary star]] system in the northern [[constellation]] of [[Boötes (constellation)|Boötes]]. It is faintly visible to the naked eye as a point of light with an [[apparent visual magnitude]] of 5.57.<ref name=Anderson_Francis_2012/> The system is located at a distance of approximately 196&nbsp;[[light year]]s from the [[Sun]] based on [[stellar parallax]],<ref name="vanLeeuwen2007"/> but is drifting closer with a [[radial velocity]] of −26&nbsp;km/s.<ref name=aa475_519/>

The binary components of this system were first measured by [[S. W. Burnham]] in 1878 and it was given the [[discovery code]] BU 612.<ref name=Mason1999/> The pair are orbiting each other with a [[orbital period|period]] of 22.46&nbsp;years with an [[orbital eccentricity|eccentricity]] (ovalness) of 0.545. The primary component is magnitude 6.35, with the secondary slightly fainter at magnitude 6.47.<ref name=aa546_A69_5/>

A third star, {{val|3.5|ul="}} away, is a 12th-magnitude common-proper-motion companion. Any orbit would take over a thousand years.<ref name=msc/>

==References== <references> <ref name=msc>{{citation |bibcode=2018ApJS..235....6T |title=The Updated Multiple Star Catalog |last1=Tokovinin |first1=Andrei |journal=The Astrophysical Journal Supplement Series |date=2018 |volume=235 |issue=1 |page=6 |doi=10.3847/1538-4365/aaa1a5 |doi-access=free |arxiv=1712.04750 }}</ref>

<ref name=Anderson_Francis_2012>{{citation | last1=Anderson | first1=E. | last2=Francis | first2=Ch. | title=XHIP: An extended hipparcos compilation | journal=Astronomy Letters | volume=38 | issue=5 | pages=331 | year=2012 | bibcode=2012AstL...38..331A | arxiv=1108.4971 | doi=10.1134/S1063773712050015 | s2cid=119257644 }}</ref>

<ref name=Zorec_Royer_2012>{{citation | last1=Zorec | first1=J. | last2=Royer | first2=F. | title=Rotational velocities of A-type stars. IV. Evolution of rotational velocities | journal=Astronomy & Astrophysics | volume=537 | page=A120 | date=January 2012 | bibcode=2012A&A...537A.120Z | arxiv=1201.2052 | doi=10.1051/0004-6361/201117691 | s2cid=55586789 }}</ref>

<ref name=Schröder_et_al_2009>{{citation | last1=Schröder | first1=C. | last2=Reiners | first2=Ansgar | last3=Schmitt | first3=Jürgen H. M. M. | title=Ca II HK emission in rapidly rotating stars. Evidence for an onset of the solar-type dynamo | journal=Astronomy and Astrophysics | volume=493 | issue=3 | pages=1099–1107 | date=January 2009 | doi=10.1051/0004-6361:200810377 | bibcode=2009A&A...493.1099S | doi-access=free | url=http://goedoc.uni-goettingen.de/goescholar/bitstream/handle/1/9690/aa10377-08.pdf?sequence=2 }}{{Dead link|date=September 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

<ref name=Mason1999>{{citation | title=Binary Star Orbits from Speckle Interferometry. I. Improved Orbital Elements of 22 Visual Systems | display-authors=1 | last1=Mason | first1=Brian D. | last2=Douglass | first2=Geoffrey G. | last3=Hartkopf | first3=William I. | journal=The Astronomical Journal | volume=117 | issue=2 | pages=1023–1036 | date=February 1999 | doi=10.1086/300748 | bibcode=1999AJ....117.1023M | s2cid=122382211 }}</ref>

<ref name="vanLeeuwen2007">{{citation | first=F. | last=van Leeuwen | title=Validation of the new Hipparcos reduction | journal=Astronomy and Astrophysics | volume=474 | issue=2 | pages=653–664 | date=November 2007 | bibcode=2007A&A...474..653V | doi=10.1051/0004-6361:20078357 | arxiv=0708.1752 | s2cid=18759600 }}</ref>

<ref name=Reiners2006>{{citation | last1=Reiners | first1=Ansgar | title=Rotation- and temperature-dependence of stellar latitudinal differential rotation | journal=Astronomy and Astrophysics | volume=446 | issue=1 |date=January 2006 | pages=267–277 | doi=10.1051/0004-6361:20053911 | bibcode=2006A&A...446..267R |arxiv = astro-ph/0509399 | s2cid=8642707 }}</ref>

<ref name=aa475_519>{{citation | display-authors=1 | last1=Holmberg | first1=J. | last2=Nordström | first2=B. | last3=Andersen | first3=J. | title=The Geneva-Copenhagen survey of the Solar neighbourhood. II. New uvby calibrations and rediscussion of stellar ages, the G dwarf problem, age-metallicity diagram, and heating mechanisms of the disk | journal=Astronomy & Astrophysics | volume=475 | issue=2 | pages=519–537 | date=2007 | arxiv=0707.1891 | bibcode=2007A&A...475..519H | doi=10.1051/0004-6361:20077221 | s2cid=119054949 }}</ref>

<ref name=aaa463_2_671>{{citation | display-authors=1 | last1=Royer | first1=F. | last2=Zorec | first2=J. | last3=Gómez | first3=A. E. | title=Rotational velocities of A-type stars. III. Velocity distributions | journal=Astronomy and Astrophysics | volume=463 | issue=2 | pages=671–682 |date=February 2007 | doi=10.1051/0004-6361:20065224 | bibcode=2007A&A...463..671R | arxiv=astro-ph/0610785 | s2cid=18475298 }}</ref>

<ref name="MERMILLIOD">{{citation | last1=Mermilliod | first1=J.-C. | title=Compilation of Eggen's UBV data, transformed to UBV (unpublished) | journal=Catalogue of Eggen's UBV Data. SIMBAD | date=1986 | bibcode=1986EgUBV........0M }}</ref>

<ref name=aa546_A69_5>{{citation | title=Dynamical Masses of a Selected Sample of Orbital Binaries | last1=Malkov | first1=O. Yu. | last2=Tamazian | first2=V. S. | last3=Docobo | first3=J. A. | last4=Chulkov | first4=D. A. | display-authors=1 | journal=Astronomy & Astrophysics | volume=546 | id=A69 | pages=5 | date=2012 | doi=10.1051/0004-6361/201219774 | doi-access=free | bibcode =2012A&A...546A..69M }}</ref>

<ref name=ORB6>{{citation | url=http://www.astro.gsu.edu/wds/orb6/orb6frames.html | title=Sixth Catalog of Orbits of Visual Binary Stars | work=United States Naval Observatory | access-date=2021-04-01 }}</ref> </references>

==External links== * [http://webviz.u-strasbg.fr/viz-bin/VizieR-S?HR%205138 HR 5138] * [http://webviz.u-strasbg.fr/viz-bin/VizieR-S?CCDM%20J13395%2b1045AB CCDM J13395+1045] * [http://aladin.u-strasbg.fr/AladinPreview?-c=BD%2B11++2589A&ident=BD%2B11++2589A&submit=Aladin+previewer Image HD 118889]

{{Stars of Boötes}}

[[Category:F-type main-sequence stars]] [[Category:Binary stars]] [[Category:Boötes]] [[Category:Durchmusterung objects]] [[Category:Henry Draper Catalogue objects|118889]] [[Category:Hipparcos objects|066640]] [[Category:Bright Star Catalogue objects|5138]]