Tau Scorpii
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Scorpius |
| Right ascension | 16h 35m 52.95285s |
| Declination | −28° 12′ 57.6615″ |
| Apparent magnitude (V) | +2.82 |
| Characteristics | |
| Evolutionary stage | main sequence |
| Spectral type | B0.2 V |
| U−B color index | −1.039 |
| B−V color index | −0.252 |
| Astrometry | |
| Radial velocity (Rv) | +2.0 km/s |
| Proper motion (μ) | RA: −9.89 mas/yr Dec.: −22.83 mas/yr |
| Parallax (π) | 6.88±0.53 mas |
| Distance | 470 ± 40 ly (150 ± 10 pc) |
| Absolute magnitude (MV) | −4.2 |
| Details | |
| Mass | 15.0±0.1, 14.5–14.7 M☉ |
| Radius | 6.42 R☉ |
| Luminosity | 25,000 L☉ |
| Surface gravity (log g) | 4.24 cgs |
| Temperature | 28,862 K |
| Metallicity [Fe/H] | −0.14 dex |
| Rotation | 41 days |
| Rotational velocity (v sin i) | 24 km/s |
| Age | 5.22 Myr |
| Other designations | |
| Paikauhale, Alniyat, Al Niyat, τ Sco, 23 Sco, CD−27 11015, FK5 620, GC 22303, HD 149438, HIP 81266, HR 6165, SAO 184481 | |
| Database references | |
| SIMBAD | data |
Tau Scorpii, Latinized from τ Scorpii, formally known as Paikauhale /ˌpaɪkaʊˈhɑːleɪ/, is a star in the southern zodiac constellation of Scorpius. The apparent visual magnitude of Tau Scorpii is +2.8, which make it among the brightest stars of the Scorpius constellation. Parallax measurements yield a distance estimate of roughly 470 light-years (150 parsecs) from Earth.