11 Librae
{{short description|Star in the constellation Libra}}
{{Starbox begin
| name = 11 Librae
}}
{{Starbox observe
| epoch = J2000
| constell = Libra
| dec = {{DEC|−02|17|56.9488}}
}}
{{Starbox character
| type = red clump
| u-b =
| variable =
}}
{{Starbox astrometry
| radial_v = {{Val|+83.60|0.06}}
| parallax = 14.92
| p_error = 0.40
}}
{{Starbox detail
| 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 }}
}}
{{Starbox reference
| Simbad = 11+Lib
}}
{{Starbox end}}
11 Librae is a single, fifth-magnitude star in the southern zodiac constellation of Libra. It is faintly visible to the naked eye with an apparent visual magnitude is 4.93. The star is moving further from the Sun with a heliocentric radial velocity of +83.6 km/s. The distance to this star, as estimated from its annual parallax shift of {{Val|14.92|0.40|ul=mas}}, is about 219 light years.
This star has a stellar classification of K0 III/IV, indicating the spectrum displays mixed traits of a giant/subgiant K-type star. Alves (2000) and Afşar et al. (2012) classify it as a red clump star, which means it is an evolved star at the cool end of the horizontal branch and is generating energy through helium fusion in its core region. 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.
References
{{reflist|refs=
{{cite simbad | title=11 Lib | access-date=2018-03-01 }}
| 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 }}
| 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=. }}
| 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=. }}
| 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=. }}
| 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 }}
| 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 }}
| 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
}}
}}
{{Stars of Libra}}
{{DEFAULTSORT:11 Librae}}
Category:Horizontal-branch stars
Category:Libra (constellation)