Pi Tauri
Pi Tauri (π Tauri) is a solitary, yellow-hued star in the zodiac constellation of Taurus. With an apparent visual magnitude of +4.69, it is bright enough to be visible to the naked eye. Although it appears to lie among the stars of the Hyades cluster, it is not itself a member, being three times farther from Earth than the cluster. The distance to this star, as determined using an annual parallax shift of 7.83 mas as seen from the Earth, is around 420 light years. At that range, the visual magnitude of the star is diminished by an extinction factor of 0.24 due to interstellar dust.
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Taurus |
| Right ascension | 04h 26m 36.37093s |
| Declination | +14° 42′ 49.6126″ |
| Apparent magnitude (V) | +4.69 |
| Characteristics | |
| Spectral type | G7 IIIa Fe-1 |
| U−B color index | +0.72 |
| B−V color index | +0.98 |
| Astrometry | |
| Radial velocity (Rv) | +31.4±0.3 km/s |
| Proper motion (μ) | RA: −9.52 mas/yr Dec.: −31.44 mas/yr |
| Parallax (π) | 7.83 ± 0.22 mas |
| Distance | 420 ± 10 ly (128 ± 4 pc) |
| Absolute magnitude (MV) | −1.27 |
| Details | |
| Mass | 3.94 M☉ |
| Radius | 21 R☉ |
| Luminosity | 229 L☉ |
| Surface gravity (log g) | 2.54 cgs |
| Temperature | 5,086 K |
| Metallicity [Fe/H] | −0.08 dex |
| Age | 17 Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is an evolved G-type giant star with a stellar classification of G7 IIIa Fe-1, where the suffix notation indicates an underabundance of iron in the spectrum. The measured angular diameter is 1.55±0.06 mas. At the estimated distance of Pi Tauri, this yields a physical size of about 21 times the radius of the Sun. It possesses nearly four times the mass of the Sun and is radiating 229 times the Sun's luminosity at an effective temperature of 5,086 K.