Alcyone (star)
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Taurus |
| Right ascension | 03h 47m 29.077s |
| Declination | +24° 06′ 18.49″ |
| Apparent magnitude (V) | 2.87 |
| Characteristics | |
| Spectral type | B7IIIe |
| U−B color index | −0.34 |
| B−V color index | −0.09 |
| Astrometry | |
| Radial velocity (Rv) | 5.40 km/s |
| Proper motion (μ) | RA: 19.34±0.39 mas/yr Dec.: −43.67±0.33 mas/yr |
| Parallax (π) | 8.09±0.42 mas |
| Distance | 136 pc |
| Absolute magnitude (MV) | −2.62 |
| Details | |
| Mass | 5.9 – 6.1 M☉ |
| Radius | 10.56 (equatorial) 8.0 (polar) R☉ |
| Luminosity | 1,750±50 L☉ |
| Surface gravity (log g) | 3.047 cgs |
| Temperature | 12,258 K |
| Rotational velocity (v sin i) | 149 km/s |
| Age | 70 Myr |
| Other designations | |
| η Tau, 25 Tau, HR 1165, HD 23630, BD+23 541, FK5 139, HIP 17702, SAO 76199, GC 4541, BDS 1875, CCDM 03474+2407 | |
| Database references | |
| SIMBAD | data |
Alcyone /ælˈsaɪəniː/, is a blue-white giant star and the brightest star in the Pleiades open cluster. At apparent magnitude 2.87, it is also the third-brightest star in the Taurus constellation. The star has the Bayer designation Eta Tauri, Latinized from η Tauri and abbreviated Eta Tau or η Tau. It is about 440 light-years distant.