{{short description|Star in the constellation Libra}} {{Starbox begin | name = 11 Librae }} {{Starbox observe | epoch = J2000 | constell = [[Libra (constellation)|Libra]] | ra = {{RA|14|51|01.07273}}<ref name=vanLeeuwen2007/> | dec = {{DEC|−02|17|56.9488}}<ref name=vanLeeuwen2007/> | appmag_v = 4.93<ref name=Anderson2012/> }} {{Starbox character | type = [[red clump]]<ref name=Alves2000/><ref name=Afsar2012/> | class = K0 III-IV<ref name=Anderson2012/> | b-v = {{Val|0.988|0.001}}<ref name=Anderson2012/> | u-b = | variable = }} {{Starbox astrometry | radial_v = {{Val|+83.60|0.06}}<ref name=Jofré2015/> | prop_mo_ra = +89.97<ref name=vanLeeuwen2007/> | prop_mo_dec = −124.57<ref name=vanLeeuwen2007/> | parallax = 14.92 | p_error = 0.40 | parallax_footnote = <ref name=vanLeeuwen2007/> | absmag_v = 0.80<ref name=Anderson2012/> }} {{Starbox detail | source = <ref name=Jofré2015/> | mass = {{Val|1.10|0.22}} | radius = {{Val|10.32|0.60}} | luminosity = {{Val|59|15|12}} | gravity = {{Val|2.42|0.09}} | temperature = {{Val|4749|54|fmt=commas}} | metal_fe = {{Val|−0.32|0.09}} | rotational_velocity = {{Val|3.74|0.48}} | age_myr = {{Val|5.05|2.67}} }} {{Starbox catalog | names = {{odlist | F=11 Lib | BD=−01°2991 | FK5= | HD=130952 | HIP=72631 | HR=5535 | SAO=140176 }}<ref name=SIMBAD/> }} {{Starbox reference | Simbad = 11+Lib }} {{Starbox end}}
'''11 Librae''' is a single,<ref name=Eggleton2008/> fifth-magnitude [[star]] in the southern [[zodiac]] [[constellation]] of [[Libra (constellation)|Libra]]. It is faintly visible to the naked eye with an [[apparent visual magnitude]] is 4.93.<ref name=Anderson2012/> The star is moving further from the Sun with a heliocentric [[radial velocity]] of +83.6 km/s.<ref name=Jofré2015/> The distance to this star, as estimated from its annual [[stellar parallax|parallax shift]] of {{Val|14.92|0.40|ul=mas}},<ref name=vanLeeuwen2007/> is about 219 [[light year]]s.
This star has a [[stellar classification]] of K0 III/IV,<ref name=Houk1999/> indicating the [[stellar spectrum|spectrum]] displays mixed traits of a [[giant star|giant]]/[[subgiant star|subgiant]] [[K-type star]]. Alves (2000) and Afşar et al. (2012) classify it as a [[red clump]] star, which means it is an [[stellar evolution|evolved]] star at the cool end of the [[horizontal branch]] and is generating energy through [[helium fusion]] in its [[stellar core|core region]].<ref name=Alves2000/><ref name=Afsar2012/> It is about five billion years old and is spinning with a [[projected rotational velocity]] of 4 km/s. The star has 1.1 times the [[mass of the Sun]] and has expanded to over 10 times the [[Sun's radius]]. It is radiating around 59 times the [[Sun's radius]] from its enlarged [[photosphere]] at an [[effective temperature]] of about 4,749 K.<ref name=Jofré2015/>
==References== <references>
<ref name=SIMBAD>{{cite simbad | title=11 Lib | access-date=2018-03-01 }}</ref>
<ref name=vanLeeuwen2007>{{citation | title=Validation of the new Hipparcos reduction | last1=van Leeuwen | first1=F. | postscript=. | journal=Astronomy and Astrophysics | volume=474 | issue=2 | pages=653–664 | year=2007 | arxiv=0708.1752 | bibcode=2007A&A...474..653V | doi=10.1051/0004-6361:20078357 | s2cid=18759600 }}</ref>
<ref name=Houk1999>{{citation | last1=Houk | first1=N. | last2=Swift | first2=C. | title=Michigan Catalogue of Two-dimensional Spectral Types for the HD Stars | journal=Michigan Spectral Survey | volume=5 | year=1999 | bibcode=1999MSS...C05....0H | postscript=. }}</ref>
<ref name=Anderson2012>{{citation | title=XHIP: An extended hipparcos compilation | last1=Anderson | first1=E. | last2=Francis | first2=Ch. | journal=Astronomy Letters | volume=38 | issue=5 | pages=331 | year=2012 | bibcode=2012AstL...38..331A | doi=10.1134/S1063773712050015 | arxiv=1108.4971 | s2cid=119257644 | postscript=. }}</ref>
<ref name=Eggleton2008>{{citation | 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 | postscript=. }}</ref>
<ref name=Alves2000>{{citation | title=K-Band Calibration of the Red Clump Luminosity | last1=Alves | first1=David R. | postscript=. | journal=The Astrophysical Journal | volume=539 | issue=2 | pages=732−741 | date=August 2000 | doi=10.1086/309278 | bibcode=2000ApJ...539..732A | arxiv=astro-ph/0003329| s2cid=16673121 }}</ref>
<ref name=Afsar2012>{{citation | title=Chemical Compositions of Thin-disk, High-metallicity Red Horizontal-branch Field Stars | display-authors=1 | last1=Afşar | first1=M. | last2=Sneden | first2=C. | last3=For | first3=B. -Q. | journal=The Astronomical Journal | postscript=. | volume=144 | issue=1 | id=20 | pages=20 | date=July 2012 | doi=10.1088/0004-6256/144/1/20 | bibcode=2012AJ....144...20A | arxiv=1205.3659| s2cid=119249237 }}</ref>
<ref name=Jofré2015>{{citation | postscript=. | title=Stellar parameters and chemical abundances of 223 evolved stars with and without planets | last1=Jofré | first1=E. | last2=Petrucci | first2=R. | last3=Saffe | first3=C. | last4=Saker | first4=L. | last5=de la Villarmois | first5=E. Artur | last6=Chavero | first6=C. | last7=Gómez | first7=M. | last8=Mauas | first8=P. J. D. | journal=Astronomy & Astrophysics | display-authors=1 | volume=574 | id=A50 | pages=46 | date=February 2015 | doi=10.1051/0004-6361/201424474 | bibcode=2015A&A...574A..50J | arxiv=1410.6422| s2cid=53666931 }}</ref>
</references>
{{Stars of Libra}}
{{DEFAULTSORT:11 Librae}} [[Category:K-type giants]] [[Category:Horizontal-branch stars]] [[Category:Libra (constellation)]] [[Category:Durchmusterung objects]] [[Category:Flamsteed objects|Librae, 11]] [[Category:Henry Draper Catalogue objects|130952]] [[Category:Hipparcos objects|072631]] [[Category:Bright Star Catalogue objects|5535]]