Alcyone (star)

Alcyone

Alcyone is the bright star at the center of the map.
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	B5IIIe
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 ± 0.42mas
Distance	136pc
Absolute magnitude (MV)	-2.62
Details
Mass	3.4-3.8 M☉
Radius	8.2 R☉
Luminosity	2,030 L☉
Surface gravity (log g)	3.047 cgs
Temperature	12,258 K
Rotational velocity (v sin i)	149 km/s
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

Coordinates: 03^h 47^m 29.0765^s, +24° 06′ 18.494″

Alcyone, designated Eta Tauri (η Tau, abbreviated Eta Tau, η Tau), is a multiple star system 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, all most probably members of the same cluster.

Eta Tauri is the star's Bayer designation. The name Alcyone originates with Greek mythology; she is one of the seven daughters of Atlas and Pleione known as the Pleiades. In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016 included a table of the first two batches of names approved by the WGSN; which included Alcyone for this star. It is now so entered in the IAU Catalog of Star Names.