5 Tauri
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Taurus | 
| Right ascension | 03h 30m 52.38296s | 
| Declination | +12° 56′ 12.0489″ | 
| Apparent magnitude (V) | +4.14 | 
| Characteristics | |
| Spectral type | K0-III | 
| U−B color index | +0.95 | 
| B−V color index | +1.09 | 
| Astrometry | |
| Radial velocity (Rv) | 14.2±0.3 km/s | 
| Proper motion (μ) | RA: 13.537 mas/yr Dec.: -2.037 mas/yr | 
| Parallax (π) | 6.1081±0.3907 mas | 
| Distance | 530 ± 30 ly (160 ± 10 pc) | 
| Absolute magnitude (MV) | −0.96 | 
| Orbit | |
| Primary | 5 Tauri A | 
| Companion | 5 Tauri B | 
| Period (P) | 960 days | 
| Semi-major axis (a) | 4.25 mas | 
| Eccentricity (e) | 0.397±0.016 | 
| Inclination (i) | 36.95° | 
| Longitude of the node (Ω) | 207.61° | 
| Periastron epoch (T) | 2,414,889.565±5.82 | 
| Argument of periastron (ω) (secondary) | 326.32±2.99° | 
| Semi-amplitude (K1) (primary) | 8.25±0.15 km/s | 
| Details | |
| 5 Tauri A | |
| Mass | 4.0±0.7 M☉ | 
| Radius | 8.5 R☉ | 
| Luminosity | 329.38 L☉ | 
| Surface gravity (log g) | 1.97 cgs | 
| Temperature | 4,644 K | 
| Metallicity [Fe/H] | 0.05 dex | 
| Rotational velocity (v sin i) | 10 km/s | 
| 5 Tauri B | |
| Mass | 1.13±0.13 M☉ | 
| Other designations | |
| f Tau, 5 Tau, BD+12°486, FK5 125, GC 4184, HD 21754, HIP 16369, HR 1066, SAO 93469, TYC 656-1725-1 | |
| Database references | |
| SIMBAD | data | 
5 Tauri is a binary star in the zodiac constellation of Taurus, located approximately 530 light years from the Sun. It is visible to the naked eye as a faint orange-hued star with an apparent visual magnitude of +4.14. It is moving further from the Earth with a heliocentric radial velocity of +14 km/s.
This is a spectroscopic binary with a period of 960 days and an eccentricity of about 0.4. The primary component is a K-type giant with a stellar classification of K0-III. It has four times the mass of the Sun and is radiating 329 times the Sun's luminosity from its photosphere at an effective temperature of 4,644 K.