Lambda Librae

Lambda Librae
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Libra
Right ascension 15h 53m 20.05463s[1]
Declination −20° 10′ 01.4177″[1]
Apparent magnitude (V) 5.03[2]
Characteristics
Spectral type B3 V[3]
U−B color index −0.584[2]
B−V color index −0.023[2]
Variable type Rotating ellipsoidal[4]
Astrometry
Radial velocity (Rv)−2.0±0.5[5] km/s
Proper motion (μ) RA: −9.81[1] mas/yr
Dec.: −26.85[1] mas/yr
Parallax (π)10.54 ± 0.91 mas[1]
Distance310 ± 30 ly
(95 ± 8 pc)
Absolute magnitude (MV)0.56[6]
Orbit[7]
Period (P)14.4829±0.0004 d
Eccentricity (e)0.27±0.09
Periastron epoch (T)2435172.380 ± 0.664 JD
Argument of periastron (ω)
(secondary)		217±17°
Semi-amplitude (K1)
(primary)		28.5±3.3 km/s
Details
Mass5.01±0.26[8] M☉
Radius3.9[9] R☉
Luminosity743[8] L☉
Surface gravity (log g)4.75 cgs
Temperature18,700[8] K
Metallicity [Fe/H]−0.27 dex
Rotational velocity (v sin i)155[10] km/s
Age282[6] Myr
Other designations
λ Lib, 45 Lib, BD−19°4249, FK5 1415, HD 142096, HIP 77811, HR 5902, SAO 183895.[11]
Database references
SIMBADdata

λ Librae (Latinised as Lambda Librae) is the Bayer designation for a binary star system in the zodiac constellation of Libra. It can be faintly seen with the naked eye, having an apparent visual magnitude of 5.03.[2] With an annual parallax shift of 10.54 mas,[1] it is roughly 310 light years from the Sun. At that distance, the visual magnitude of this system is diminished by an extinction factor of 0.22 due to interstellar dust.[6] It is 0.1 degree north of the ecliptic.

This is a single-lined spectroscopic binary star system with an orbital period of 14.48 days and an eccentricity of 0.27.[7] The visible component is a B-type main sequence star with a stellar classification of B3 V.[3] It is a helium-weak chemically peculiar star[12] and a rotating ellipsoidal variable.[4] The star has an estimated 3.9[9] times the radius of the Sun and five times the Sun's mass.[8] This is a candidate Vega-like star, meaning that it shows an infrared excess characteristic of a circumstellar debris disk.[13] The system is a source of X-ray emission.[14]

  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 apjs15 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. ^ a b Cite error: The named reference Hoffleit1996 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference deBruijne2012 was invoked but never defined (see the help page).
  6. ^ a b c Cite error: The named reference Gontcharov2012 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Pourbaix2004 was invoked but never defined (see the help page).
  8. ^ a b c d Cite error: The named reference Hohle2010 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference PasinettiFracassini2001 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Abt2002 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Renson2009 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Saffe2008 was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference Berghoefer1996 was invoked but never defined (see the help page).