Kappa Librae

Kappa Librae
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Libra
Right ascension 15h 41m 56.79858s[1]
Declination −19° 40′ 43.7745″[1]
Apparent magnitude (V) 4.72[2]
Characteristics
Spectral type K5 III[3]
U−B color index +1.94[2]
B−V color index +1.58[2]
Astrometry
Radial velocity (Rv)−4.5±1.5[4] km/s
Proper motion (μ) RA: −32.06[1] mas/yr
Dec.: −103.15[1] mas/yr
Parallax (π)10.57 ± 1.40 mas[1]
Distanceapprox. 310 ly
(approx. 90 pc)
Absolute magnitude (MV)−0.62[5]
Details
Radius38[6] R☉
Luminosity296[7] L☉
Temperature3,930[7] K
Other designations
κ Lib, 43 Lib, BD−19° 4188, FK5 1413, HD 139997, HIP 76880, HR 5838, SAO 159442[8]
Database references
SIMBADdata

Kappa Librae, Latinized from κ Librae, is the Bayer designation for a star system in the zodiac constellation of Libra. Its apparent visual magnitude is 4.72,[2] so it can be seen with the naked eye. The annual parallax shift of 10.57 mas[1] 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.[9] The visible component is an evolved K-type giant star with a stellar classification of K5 III.[3] It is a suspected variable star with a brightness that ranges between 4.70 and 4.75.[10] The measured angular diameter is 3.71±0.10 mas,[11] which, at the estimated distance of Kappa Librae, yields a physical size of about 38 times the radius of the Sun.[6] It radiates 296 times the solar luminosity from its outer atmosphere at an effective temperature of 3,930 K.[7]

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).[12]

  1. ^ a b c d e f Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference Johnson1966 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference houk1978 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference deBruijne2012 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference lang2006 was invoked but never defined (see the help page).
  7. ^ a b c Cite error: The named reference Mcdonald2012 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Makarov2005 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Samus2004 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Richichi2005 was invoked but never defined (see the help page).
  12. ^ Ian Ridpath's Startales - Libra the Scales