Tau2 Lupi
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Lupus |
| Right ascension | 14h 26m 10.81378s |
| Declination | −45° 22′ 45.4023″ |
| Apparent magnitude (V) | 4.34 (4.93 + 5.55) |
| Characteristics | |
| Spectral type | F4 IV + A7: |
| U−B color index | +0.16 |
| B−V color index | +0.43 |
| Astrometry | |
| Radial velocity (Rv) | −0.60±1.60 km/s |
| Proper motion (μ) | RA: +14.62 mas/yr Dec.: −7.33 mas/yr |
| Parallax (π) | 10.22±0.31 mas |
| Distance | 319 ± 10 ly (98 ± 3 pc) |
| Absolute magnitude (MV) | −0.62 |
| Orbit | |
| Period (P) | 26.2 yr |
| Semi-major axis (a) | 0.125″ |
| Eccentricity (e) | 0.94 |
| Inclination (i) | 56.0° |
| Longitude of the node (Ω) | 175.7° |
| Periastron epoch (T) | 1969.1 |
| Argument of periastron (ω) (secondary) | 191.0° |
| Details | |
| Luminosity | 150 L☉ |
| Rotational velocity (v sin i) | 0 km/s |
| Other designations | |
| τ2 Lup, CD−44°9323, HD 126354, HIP 70576, HR 5396, SAO 224920 | |
| Database references | |
| SIMBAD | data |
Tau2 Lupi, Latinized from τ2 Lup, is a binary star system in the constellation Lupus. It is visible to the naked eye with a combined apparent visual magnitude of 4.34. Based upon an annual parallax shift of 10.22 mas as seen from Earth, it is located around 319 light years from the Sun. The two components orbit each other with a period of 26.2 years and a high eccentricity of 0.94. The brighter component is a magnitude 4.93 subgiant star with a stellar classification of F4 IV. Its companion is an A-type star with visual magnitude 5.55 and class A7:.