5 Tauri
Binary star system in the constellation Taurus
From Wikipedia, the free encyclopedia
5 Tauri is a binary star[6] 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.[2]
 | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Taurus |
| Right ascension | 03h 30m 52.38296s[1] |
| Declination | +12° 56′ 12.0489″[1] |
| Apparent magnitude (V) | +4.14[2] |
| Characteristics | |
| Spectral type | K0-III[3] |
| U−B color index | +0.95[4] |
| B−V color index | +1.09[4] |
| Astrometry | |
| Radial velocity (Rv) | 14.2±0.3[2] km/s |
| Proper motion (μ) | RA: 13.537[1] mas/yr Dec.: -2.037[1] mas/yr |
| Parallax (π) | 6.1081±0.3907 mas[1] |
| Distance | 530 ± 30 ly (160 ± 10 pc) |
| Absolute magnitude (MV) | −0.96[2] |
| Orbit[5] | |
| Primary | 5 Tauri A |
| Name | 5 Tauri B |
| Period (P) | 960 days |
| Semi-major axis (a) | 4.25 mas[6] |
| Eccentricity (e) | 0.397±0.016 |
| Inclination (i) | 36.95[6]° |
| Longitude of the node (Ω) | 207.61[6]° |
| 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[7] M☉ |
| Radius | 8.5[8] R☉ |
| Luminosity | 329.38[2] L☉ |
| Surface gravity (log g) | 1.97[9] cgs |
| Temperature | 4,644[9] K |
| Metallicity [Fe/H] | 0.05[9] dex |
| Rotational velocity (v sin i) | 10[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[11] | |
| Database references | |
| SIMBAD | data |
This is a spectroscopic binary with a period of 960 days and an eccentricity of about 0.4.[5] The primary component is a K-type giant with a stellar classification of K0-III.[3] It has four times the mass of the Sun[7] and is radiating 329 times the Sun's luminosity from its photosphere[2] at an effective temperature of 4,644 K.[9]