Alcyone (star)

Alcyone

Alcyone in the Pleiades cluster (circled)
Observation data Epoch J2000      Equinox J2000
Constellation	Taurus
Right ascension	03h 47m 29.077s[1]
Declination	24° 06′ 18.49″[1]
Apparent magnitude (V)	2.87[2]
Characteristics
Spectral type	B5IIIe[3]
U−B color index	−0.34[2]
B−V color index	−0.09[2]
Astrometry
Radial velocity (Rv)	5.40[4] km/s
Proper motion (μ)	RA: 19.34±0.39[1] mas/yr Dec.: −43.67±0.33[1] mas/yr
Parallax (π)	8.09 ± 0.42 mas[1]
Distance	136[5] pc
Absolute magnitude (MV)	−2.62[6]
Details
Mass	5.9 – 6.1[7] M☉
Radius	9.3±0.7[8] R☉
Luminosity	2,030[9] L☉
Surface gravity (log g)	3.047[3] cgs
Temperature	12,258[3] K
Rotational velocity (v sin i)	149[3] km/s
Age	70[10] 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/,^[11] designated η Tauri (Eta Tauri, abbreviated Eta Tau, η Tau), is a star in the constellation of Taurus. Approximately 440 light-years from the Sun, it is the brightest star in the Pleiades open cluster, which is a young cluster, around 100 million years old. There are a number of fainter stars very close to Alcyone, some of which are members of the same cluster.^{[citation needed]}