Lambda Librae
Binary star system in the constellation Libra / From Wikipedia, the free encyclopedia
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.
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] |
Distance | 310 ± 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 | |
Mass | 5.01±0.26[8] M☉ |
Radius | 3.9[9] R☉ |
Luminosity | 743[8] L☉ |
Surface gravity (log g) | 4.75 cgs |
Temperature | 18,700[8] K |
Metallicity [Fe/H] | −0.27 dex |
Rotational velocity (v sin i) | 155[10] km/s |
Age | 282[6] Myr |
Other designations | |
Database references | |
SIMBAD | data |
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]