Sigma2 Tauri
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Taurus |
| Right ascension | 04h 39m 16.50230s |
| Declination | +15° 55′ 04.7029″ |
| Apparent magnitude (V) | 4.70 |
| Characteristics | |
| Spectral type | A5 Vn |
| U−B color index | +0.13 |
| B−V color index | +0.14 |
| Astrometry | |
| Radial velocity (Rv) | +40.8±1.2 km/s |
| Proper motion (μ) | RA: +83.17 mas/yr Dec.: −20.97 mas/yr |
| Parallax (π) | 20.97±0.27 mas |
| Distance | 156 ± 2 ly (47.7 ± 0.6 pc) |
| Details | |
| Mass | 1.71 M☉ |
| Radius | 1.9 R☉ |
| Luminosity | 22.5 L☉ |
| Surface gravity (log g) | 3.96 cgs |
| Temperature | 8,165±278 K |
| Metallicity [Fe/H] | 0.10±0.11 dex |
| Rotational velocity (v sin i) | 128 km/s |
| Age | 258 Myr |
| Other designations | |
| 92 Tauri, BD+15°666, FK5 2345, HD 29488, HIP 21683, HR 1479, SAO 94054, WDS J04393+1555A | |
| Database references | |
| SIMBAD | data |
Sigma2 Tauri (σ2 Tauri) is the Bayer designation for a white-hued star in the zodiac constellation of Taurus. It has an apparent visual magnitude of +4.70, which indicates it is visible to the naked eye. Based upon parallax measurements, σ2 Tauri is about 156 light-years distant.
σ2 Tauri is a solitary A-type main sequence star with a stellar classification of A5 Vn. The 'n' suffix indicates the lines are "nebulous" due to rapid rotation, and indeed it is spinning with a projected rotational velocity of 128 km/s. The star is an estimated 258 million years old, with 1.7 times the mass of the Sun. It is radiating 22.5 times the Sun's luminosity from its photosphere at an effective temperature of around 8,165 K. The star is considered a member of the Hyades cluster.
In Chinese astronomy, σ2 Tauri is called 附耳, Pinyin: Fùěr, meaning Whisper, because this star is marking itself and stands alone in the Whisper asterism of the Net mansion (see: Chinese constellation).