View source for 6 Boötis

{{Short description|Star in the constellation Boötes}}
{{about-distinguish|e Boötis|epsilon Boötis{{!}}ε (epsilon) Boötis}}
{{Starbox begin}}
{{Starbox image
| image = [[Image:6 Boötis.jpg|300px]]
| caption = 6 Boötis in optical light.
}}
{{Starbox observe
 | epoch = [[J2000.0]]
 | constell = [[Boötes]]
 | ra = {{RA|13|49|42.82223}}<ref name=GaiaDR2/>
 | dec = {{DEC|+21|15|50.8580}}<ref name=GaiaDR2/>
 | appmag_v = 4.92<ref name=Anderson2012/>
}}
{{Starbox character
 | type  = 
 | class = {{nowrap|K4 III<ref name=Yoss1997/> + M8 V<ref name=Griffin1985/>}}
 | b-v   = {{Val|1.432|0.013}}<ref name=Anderson2012/>
 | variable = 
}}
{{Starbox astrometry
 | radial_v = {{Val|−3.71|0.48}}<ref name=GaiaDR2/>
 | prop_mo_ra  = +33.773<ref name=GaiaDR2/>
 | prop_mo_dec = +10.842<ref name=GaiaDR2/>
 | parallax = 7.1527
 | p_error  = 0.3659
 | parallax_footnote = <ref name=GaiaDR2/>
 | absmag_v = −0.49<ref name=Anderson2012/>
}}
{{Starbox orbit
 | reference = <ref name=Griffin1985/>
 | period_unitless = {{Val|944|8|u=days}}
 | eccentricity = {{Val|0.41|0.09}}
 | periastron = {{Val|2444739.5|31.0|ul=JD|fmt=commas}}
 | periarg = {{Val|359|15}}
 | k1 = {{Val|1.19|0.15}}
}}
{{Starbox detail
 | source  = 
 | mass    = 
 | radius  = 38<ref name=lang2006/>
 | gravity = 1.910<ref name=McWilliam1990/>
 | luminosity  = 430.124<ref name=GaiaDR2/>
 | temperature = 4,050<ref name=McWilliam1990/>
 | metal_fe = −0.24<ref name=McWilliam1990/>
 | rotational_velocity = 2.0<ref name=DeMedeiros2002/>
 | age_myr  = 
}}
{{Starbox catalog
 | names = {{odlist | B=e&nbsp;Boötis | F=53 Cam | BD=+21°2578 | FK5=3098 | HD=120539 | HIP=67480 | HR=5201 | SAO=83015 | GC=18683 }}<ref name=SIMBAD/>
}}
{{Starbox reference
 | Simbad = 6+Boo
}}
{{Starbox end}}

'''6 Boötis''' is a [[binary star]]<ref name=Griffin1985/> system in the northern [[constellation]] of [[Boötes]],<ref name=SIMBAD/> located around 460&nbsp;[[light year]]s away from the Sun.<ref name=GaiaDR2/> It has the [[Bayer designation]] '''e Boötis'''; ''6 Boötis'' is the [[Flamsteed designation]].<ref name=SIMBAD/> The system is visible to the naked eye as a faint, orange-hued star with an [[apparent visual magnitude]] of 4.92.<ref name=Anderson2012/> It is moving closer to the Earth with a heliocentric [[radial velocity]] of −3&nbsp;km/s.<ref name=Anderson2012/>

This is a single-lined [[spectroscopic binary]] system with an [[orbital period]] of {{Convert|944|days|years|abbr=off|disp=out}} and an [[orbital eccentricity|eccentricity]] of 0.4.<ref name=Griffin1985/> The visible component is an [[stellar evolution|evolved]] [[giant star]] with a [[stellar classification]] of K4&nbsp;III.<ref name=Yoss1997/> Its measured [[angular diameter]] is {{Val|2.53|0.12|u=[[milliarcsecond|mas]]}}.<ref name=Richichi2005/> At the estimated distance of the star, this yields a physical size of about 38 times the [[Solar radius|radius of the Sun]].<ref name=lang2006/> The star is radiating 430<ref name=GaiaDR2/> times the [[luminosity of the Sun]] from its enlarged [[photosphere]] at an [[effective temperature]] of 4,050&nbsp;K.<ref name=McWilliam1990/> Its companion is probably a low mass [[red dwarf]] of around class M8&nbsp;V.<ref name=Griffin1985/>

==References==
{{reflist|refs=

<ref name=GaiaDR2>{{cite DR2|1250169120491310720}}</ref>

<ref name=SIMBAD>{{cite simbad | title=6 Boo | access-date=2019-04-23 }}</ref>

<ref name=Anderson2012>{{citation
 | title=XHIP: An extended hipparcos compilation
 | last1=Anderson | first1=E. | last2=Francis | first2=Ch.
 | journal=Astronomy Letters | postscript=.
 | volume=38 | issue=5 | pages=331 | year=2012
 | bibcode=2012AstL...38..331A | arxiv=1108.4971
 | doi=10.1134/S1063773712050015 | s2cid=119257644 }}</ref>

<ref name=Griffin1985>{{citation
 | title=Spectroscopic binaries near the North Galactic Pole. Paper 12 : 6 Bootis.
 | last1=Griffin | first1=R. F. | postscript=.
 | journal=Journal of Astrophysics and Astronomy
 | volume=6 | pages=77–83 | date=June 1985
 | doi=10.1007/BF02715079 | bibcode=1985JApA....6...77G | s2cid=124682374 }}</ref>

<ref name=McWilliam1990>{{citation
 | last1=McWilliam | first1=Andrew
 | title=High-resolution spectroscopic survey of 671 GK giants. I - Stellar atmosphere parameters and abundances
 | journal=Astrophysical Journal Supplement Series
 | volume=74 | pages=1075–1128 | date=December 1990
 | doi=10.1086/191527 | bibcode=1990ApJS...74.1075M | doi-access=free }}</ref>

<ref name=DeMedeiros2002>{{citation
 | title=The Rotation of Binary Systems with Evolved Components
 | display-authors=1 | last1=De Medeiros | first1=J. R.
 | last2=Da Silva | first2=J. R. P. | last3=Maia | first3=M. R. G.
 | journal=The Astrophysical Journal | postscript=.
 | volume=578 | issue=2 | pages=943–950 | date=October 2002
 | doi=10.1086/342613 | bibcode=2002ApJ...578..943D
 | arxiv=astro-ph/0207288 | s2cid=16196039 }}</ref>

<ref name=Richichi2005>{{citation
 | display-authors=1 | last1=Richichi | first1=A.
 | last2=Percheron | first2=I. | last3=Khristoforova | first3=M.
 | title=CHARM2: An updated Catalog of High Angular Resolution Measurements
 | journal=Astronomy and Astrophysics | postscript=.
 | volume=431 | issue=2 | pages=773–777 | date=February 2005
 | doi=10.1051/0004-6361:20042039 | bibcode=2005A&A...431..773R | doi-access=free }}</ref>

<ref name=lang2006>{{citation
 | first1=Kenneth R. | last1=Lang
 | title=Astrophysical formulae | postscript=.
 | volume=1 | series=Astronomy and astrophysics library
 | edition=3rd | publisher=[[Birkhäuser]] | date=2006
 | isbn=3-540-29692-1 | url=https://books.google.com/books?id=OvTjLcQ4MCQC&pg=PA41
}} The radius (R<sub>*</sub>) is given by:
:<math>\begin{align} 2\cdot R_*
 & = \frac{(140\cdot 2.53\cdot 10^{-3})\ \text{AU}}{0.0046491\ \text{AU}/R_{\bigodot}} \\
 & \approx 76.2\cdot R_{\bigodot}
\end{align}</math></ref>

<ref name=Yoss1997>{{citation
 | title=Radial Velocities and DDO, BV Photometry of Henry Draper G5-M Stars Near the North Galactic Pole
 | last1=Yoss | first1=K. M. | last2=Griffin | first2=R. F.
 | journal=Journal of Astrophysics and Astronomy
 | volume=18 | page=161 | date=September 1997 | issue=2–3 | postscript=.
 | doi=10.1007/BF02714877 | bibcode=1997JApA...18..161Y | s2cid=123221180 }}</ref>

}}

{{Stars of Boötes}}

{{DEFAULTSORT:6 Bootis}}
[[Category:K-type giants]]
[[Category:M-type main-sequence stars]]
[[Category:Spectroscopic binaries]]
[[Category:Boötes]]
[[Category:Bayer objects|Bootis, e]]
[[Category:Durchmusterung objects]]
[[Category:Flamsteed objects|Bootis, 06]]
[[Category:Henry Draper Catalogue objects|120539]]
[[Category:Hipparcos objects|067480]]
[[Category:Bright Star Catalogue objects|5201]]