Mu Lupi
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Lupus |
| Right ascension | 15h 18m 32.02296s |
| Declination | −47° 52′ 30.9957″ |
| Apparent magnitude (V) | 4.29 |
| Characteristics | |
| Spectral type | B8 Ve (AB) + A2/3(V) (C) |
| U−B color index | −0.41 |
| B−V color index | −0.03 |
| Astrometry | |
| Radial velocity (Rv) | +14.90±1.78 km/s |
| Proper motion (μ) | RA: −29.59 mas/yr Dec.: −35.07 mas/yr |
| Parallax (π) | 9.72±0.71 mas |
| Distance | 340 ± 20 ly (103 ± 8 pc) |
| Absolute magnitude (MV) | −0.57 |
| Orbit | |
| Primary | A |
| Name | B |
| Period (P) | 772 yr |
| Semi-major axis (a) | 1.657″ |
| Eccentricity (e) | 0.43 |
| Inclination (i) | 114.6° |
| Periastron epoch (T) | 2048 |
| Orbit | |
| Primary | Ca |
| Name | Cb |
| Period (P) | 12.353±0.004 days |
| Eccentricity (e) | 0.4±0.1 |
| Periastron epoch (T) | 2,455,177.7 JD |
| Argument of periastron (ω) (primary) | 324±18° |
| Semi-amplitude (K1) (primary) | 2.4±0.4 km/s |
| Details | |
| A | |
| Mass | 3.16 M☉ |
| Rotational velocity (v sin i) | 280 km/s |
| B | |
| Mass | 3.07 M☉ |
| Rotational velocity (v sin i) | 50 km/s |
| Ca | |
| Mass | 1.78 M☉ |
| Temperature | 8,500 K |
| Cb | |
| Mass | 0.05 M☉ |
| Other designations | |
| μ Lup, CD−47°9860, FK5 , HD 135734, HIP 74911, HR 5683, SAO 225638, WDS J15185-4753AB | |
| Database references | |
| SIMBAD | data |
Mu Lupi (μ Lup) is a system of three confirmed stars and one brown dwarf in the southern constellation of Lupus. It is visible to the naked eye with an apparent visual magnitude of 4.29 and lies roughly 340 light-years from the Sun.
Two of the components of this system, A and B, form a pair with an angular separation of 1.657 arcseconds. An orbital solution gives an orbital period of 772 years. Component C, an A-type main-sequence star, lies at an angular separation of 23.3 arcseconds from the AB pair, and is itself a binary with an orbital period of 12.35 days. Its companion has a mass of 0.05 M☉, too low to fuse hydrogen, and thus it is considered a brown dwarf. A fifth component, not confirmed to be a physical companion, lies at an angular separation of 6.10 arcseconds from component AB, and with a mass of 0.05 M☉ is also a brown dwarf.