126 Tauri
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Taurus |
| Right ascension | 05h 41m 17.71768s |
| Declination | +16° 32′ 02.9253″ |
| Apparent magnitude (V) | 4.836 (5.04 / 6.56) |
| Characteristics | |
| Spectral type | B3 IV |
| U−B color index | −0.64 |
| B−V color index | −0.12 |
| Astrometry | |
| Radial velocity (Rv) | +21.90±0.9 km/s |
| Proper motion (μ) | RA: +3.50 mas/yr Dec.: −15.47 mas/yr |
| Parallax (π) | 5.13±0.81 mas |
| Distance | approx. 600 ly (approx. 190 pc) |
| Orbit | |
| Primary | A |
| Companion | B |
| Period (P) | 118±7 yr |
| Semi-major axis (a) | 0.185±0.007″ |
| Eccentricity (e) | 0.78±0.01 |
| Inclination (i) | 68.9±0.7° |
| Longitude of the node (Ω) | 63.5±0.8° |
| Periastron epoch (T) | 61118±35 |
| Argument of periastron (ω) (secondary) | 338±4° |
| Orbit | |
| Primary | Ba |
| Companion | Bb |
| Period (P) | 4.77095±0.00023 d |
| Semi-major axis (a) | 0.055±0.013 mas |
| Eccentricity (e) | 0.0 |
| Inclination (i) | 30±19° |
| Longitude of the node (Ω) | 310±14° |
| Periastron epoch (T) | 59529.10±0.01 |
| Argument of periastron (ω) (secondary) | 0.0° |
| Semi-amplitude (K1) (primary) | 72.9±0.3 km/s |
| Details | |
| 128 Tau A | |
| Mass | 6.14 M☉ |
| Luminosity | 2,061 L☉ |
| Temperature | 17,900 K |
| Ba | |
| Mass | 3.19 M☉ |
| B | |
| Mass | 1.65 M☉ |
| Other designations | |
| BD+16°841, HD 37711, HIP 26777, HR 1946, SAO 94759 | |
| Database references | |
| SIMBAD | data |
126 Tauri (126 Tau) is a triple star system in the constellation Taurus, approximately 600 light years away. Its apparent magnitude is 4.83, making it visible to the naked eye with dark skies.
126 Tauri is a well-known binary star with the two components in an eccentric orbit of over a hundred years. The secondary, component B, has also shown radial velocity variations that indicate an unseen companion in a 4.77-day orbit.
The combined spectral class is typically quoted as B3IV, occasionally B3V. The primary alone has been classed as B3V, although the two components have been individually measured at B8V and B7V.