Tau Centauri
Tau Centauri, Latinized from τ Centauri, is a solitary star in the southern constellation of Centaurus. It is visible to the naked eye with an apparent visual magnitude of +3.86. The distance to this star, based upon an annual parallax shift of 24.85 mas, is 131 light years. There is a 98% chance that it is a co-moving companion of Gamma Centauri; the two stars have an estimated separation of 1.7 ly (0.53 pc).
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Centaurus |
| Right ascension | 12h 37m 42.16377s |
| Declination | −48° 32′ 28.6899″ |
| Apparent magnitude (V) | +3.86 |
| Characteristics | |
| Spectral type | A0 V or A1 IVnn |
| U−B color index | +0.04 |
| B−V color index | +0.06 |
| Astrometry | |
| Radial velocity (Rv) | +5.5±2.3 km/s |
| Proper motion (μ) | RA: −186.26 mas/yr Dec.: −6.01 mas/yr |
| Parallax (π) | 24.85 ± 0.53 mas |
| Distance | 131 ± 3 ly (40.2 ± 0.9 pc) |
| Absolute magnitude (MV) | +0.83 |
| Details | |
| Mass | 2.31 M☉ |
| Radius | 2.2 R☉ |
| Luminosity | 42 L☉ |
| Surface gravity (log g) | 4.02±0.14 cgs |
| Temperature | 10,533±358 K |
| Rotational velocity (v sin i) | 296.8±3.8 km/s |
| Age | 132 Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is an A-type star with stellar classifications of A0 V or A1 IVnn, indicating it may be a main sequence star or a more evolved subgiant star. It is around 132 million years old and is spinning rapidly with a projected rotational velocity of 296.8 km/s. This is giving the star an oblate shape, with an estimated equatorial girth that is 30% larger than the polar radius. The star has an estimated 2.3 times the mass of the Sun and 2.2 times the Sun's radius.