Lambda Librae

Lambda Librae

A light curve for Lambda Librae, adapted from Wraight et al. (2012)[1]
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Libra
Right ascension 15h 53m 20.05463s[2]
Declination −20° 10′ 01.4177″[2]
Apparent magnitude (V) 5.03[3]
Characteristics
Spectral type B3 V[4]
U−B color index −0.584[3]
B−V color index −0.023[3]
Variable type Rotating ellipsoidal[5]
Astrometry
Radial velocity (Rv)−2.0±0.5[6] km/s
Proper motion (μ) RA: −9.81[2] mas/yr
Dec.: −26.85[2] mas/yr
Parallax (π)10.54 ± 0.91 mas[2]
Distance310 ± 30 ly
(95 ± 8 pc)
Absolute magnitude (MV)0.56[7]
Orbit[8]
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[9] M☉
Radius3.9[10] R☉
Luminosity743[9] L☉
Surface gravity (log g)4.75 cgs
Temperature18,700[9] K
Metallicity [Fe/H]−0.27 dex
Rotational velocity (v sin i)155[11] km/s
Age282[7] Myr
Other designations
λ Lib, 45 Lib, BD−19°4249, FK5 1415, HD 142096, HIP 77811, HR 5902, SAO 183895.[12]
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.[3] With an annual parallax shift of 10.54 mas,[2] 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.[7] 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.[8] The visible component is a B-type main sequence star with a stellar classification of B3 V.[4] It is a helium-weak chemically peculiar star[13] and a rotating ellipsoidal variable.[5] The star has an estimated 3.9[10] times the radius of the Sun and five times the Sun's mass.[9] This is a candidate Vega-like star, meaning that it shows an infrared excess characteristic of a circumstellar debris disk.[14] The system is a source of X-ray emission.[15]

  1. ^ Cite error: The named reference Wraight was invoked but never defined (see the help page).
  2. ^ a b c d e f Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  3. ^ a b c d Cite error: The named reference apjs15 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference houk1978 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Hoffleit1996 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference deBruijne2012 was invoked but never defined (see the help page).
  7. ^ a b c Cite error: The named reference Gontcharov2012 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference Pourbaix2004 was invoked but never defined (see the help page).
  9. ^ a b c d Cite error: The named reference Hohle2010 was invoked but never defined (see the help page).
  10. ^ a b Cite error: The named reference PasinettiFracassini2001 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Abt2002 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Renson2009 was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference Saffe2008 was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference Berghoefer1996 was invoked but never defined (see the help page).