Kappa Librae
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Libra |
| Right ascension | 15h 41m 56.79858s |
| Declination | −19° 40′ 43.7745″ |
| Apparent magnitude (V) | 4.72 |
| Characteristics | |
| Spectral type | K5 III |
| U−B color index | +1.94 |
| B−V color index | +1.58 |
| Astrometry | |
| Radial velocity (Rv) | −4.5±1.5 km/s |
| Proper motion (μ) | RA: −32.06 mas/yr Dec.: −103.15 mas/yr |
| Parallax (π) | 10.57±1.40 mas |
| Distance | approx. 310 ly (approx. 90 pc) |
| Absolute magnitude (MV) | −0.62 |
| Details | |
| Mass | 1.6 M☉ |
| Radius | 38 R☉ |
| Luminosity | 388 L☉ |
| Surface gravity (log g) | 1.35 cgs |
| Temperature | 3,875 K |
| Metallicity [Fe/H] | −0.39 dex |
| Other designations | |
| κ Lib, 43 Lib, BD−19°4188, FK5 1413, HD 139997, HIP 76880, HR 5838, SAO 159442 | |
| Database references | |
| SIMBAD | data |
Kappa Librae is a star system in the zodiac constellation of Libra. Its name is a Bayer designation that is Latinized from κ Librae, and abbreviated Kappa Lib or κ Lib. Its apparent visual magnitude is 4.72, so it can be seen with the naked eye. The annual parallax shift of 10.57 mas indicates it is roughly 310 light years away. It is positioned 0.02 degrees south of the ecliptic.
The star shows acceleration components in its proper motion, indicating with high probability that it is an astrometric binary. The visible component is an evolved K-type giant star with a stellar classification of K5 III. It is a suspected variable star with a brightness that ranges between 4.70 and 4.75. Kappa Librae is 38 times larger than the Sun, and is radating 388 times the solar luminosity from its outer atmosphere at an effective temperature of 3,875 K.
In Chinese astronomy, Kappa Librae is called 日, Pinyin: Rì, meaning Sun, because this star is marking itself and stand alone in Sun asterism, Room mansion (see : Chinese constellation).