Lambda Lupi
Lambda Lupi, Latinized from λ Lupi, is a triple star system in the southern constellation of Lupus. It is visible to the naked eye with a combined apparent visual magnitude of 4.04. Based upon an annual parallax shift of just 4.20 mas as seen from Earth, it is located roughly 800 light years from the Sun. The system has a peculiar velocity of 27.4±4.9 km/s relative to its neighbors, making it a candidate runaway star system. It is a member of the Upper Centaurus–Lupus sub-group in the Scorpius–Centaurus OB association.
Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
---|---|
Constellation | Lupus |
Right ascension | 15h 08m 50.61639s |
Declination | −45° 16′ 47.4950″ |
Apparent magnitude (V) | 4.04 (4.43 + 5.23) |
Characteristics | |
Spectral type | B3 V (B3 V + B3 V) |
U−B color index | −0.67 |
B−V color index | −0.18 |
Astrometry | |
Radial velocity (Rv) | +9.80±1.78 km/s |
Proper motion (μ) | RA: −15.88 mas/yr Dec.: −26.80 mas/yr |
Parallax (π) | 4.20 ± 0.66 mas |
Distance | approx. 800 ly (approx. 240 pc) |
Absolute magnitude (MV) | −2.75 |
Orbit | |
Period (P) | 70.8±0.8 yr |
Semi-major axis (a) | 0.2597±0.0021″ |
Eccentricity (e) | 0.6283±0.0090 |
Inclination (i) | 71.59±0.41° |
Longitude of the node (Ω) | 26.64±0.61° |
Periastron epoch (T) | 1997.907 ± 0.105 |
Argument of periastron (ω) (secondary) | 299.9±1.1° |
Details | |
λ Lup A | |
Mass | 8.14 M☉ |
Rotational velocity (v sin i) | 135 km/s |
Age | 28.1±4.1 Myr |
λ Lup B | |
Mass | 5.84 M☉ |
Other designations | |
Database references | |
SIMBAD | data |
The two visible components of this system orbit each other over a period of 70.8 years with a large eccentricity of 0.63. The primary component has a visual magnitude of 4.43, while the secondary is of magnitude 5.23. Both are B-type main sequence stars with a stellar classification of B3 V. One of the pair is itself a double-lined spectroscopic binary, making this a triple star system.