11 Librae

11 Librae is a single,^[7] 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.^[2] The star is moving further from the Sun with a heliocentric radial velocity of +83.6 km/s.^[5] The distance to this star, as estimated from its annual parallax shift of 14.92±0.40 mas,^[1] is about 219 light years.

11 Librae

Observation data Epoch J2000      Equinox J2000
Constellation	Libra
Right ascension	14h 51m 01.07273s[1]
Declination	−02° 17′ 56.9488″[1]
Apparent magnitude (V)	4.93[2]
Characteristics
Evolutionary stage	red clump[3][4]
Spectral type	K0 III-IV[2]
B−V color index	0.988±0.001[2]
Astrometry
Radial velocity (Rv)	+83.60±0.06[5] km/s
Proper motion (μ)	RA: +89.97[1] mas/yr Dec.: −124.57[1] mas/yr
Parallax (π)	14.92±0.40 mas[1]
Distance	219 ± 6 ly (67 ± 2 pc)
Absolute magnitude (MV)	0.80[2]
Details[5]
Mass	1.10±0.22 M☉
Radius	10.32±0.60 R☉
Luminosity	59+15 −12 L☉
Surface gravity (log g)	2.42±0.09 cgs
Temperature	4,749±54 K
Metallicity [Fe/H]	−0.32±0.09 dex
Rotational velocity (v sin i)	3.74±0.48 km/s
Age	5.05±2.67 Myr
Other designations
11 Lib, BD−01°2991, HD 130952, HIP 72631, HR 5535, SAO 140176[6]
Database references
SIMBAD	data

This star has a stellar classification of K0 III/IV,^[8] 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.^[3][4] 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.^[5]