Alkiones (star)

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Star
Alkione (η Tauri)
Center left in the Pleiades: Alkione
Center left in the Pleiades: Alkione
AladinLite
Observation
dates equinoxJ2000.0 , epoch : J2000.0
Constellation bull
Right ascension 03 h 47 m 29.08 s
declination + 24 ° 06 ′ 18.5 ″
Apparent brightness 2.87 mag
Typing
B − V color index (−0.09) 
U − B color index (−0.34) 
R − I index (−0.04) 
Spectral class B5 IIIe
Variable star type Yes 
Astrometry
Radial velocity (5.4 ± 1.2) km / s
parallax (8.09 ± 0.42)  mas
distance (400 ± 20)  ly
(125)  pc
Proper movement 
Rec. Share: (19.3 ± 0.4)  mas / a
Dec. portion: (−43.7 ± 0.3)  mas / a
Physical Properties
Dimensions (6.0 ± 0.1)  M
radius (9.3 ± 0.7)  R
Effective temperature (12258)  K.
Other names
and catalog entries
Bayer name η Tauri
Flamsteed name 25 Tauri
Bonn survey BD + 23 ° 541
Bright Star Catalog HR 1165 [1]
Henry Draper Catalog HD 23630 [2]
Hipparcos catalog HIP 17702 [3]
SAO catalog SAO 76199 [4]
Tycho catalog TYC 1800-2202-1 [5]
2MASS catalog 2MASS J03472908 + 2406184 [6]
Other names FK5 139

Alkione or Alcyone (Eta Tauri, η Tauri) is the brightest star in the Pleiades star cluster . It takes its name from the Pleiad Alkione , who in Greek mythology was the mother of Aithusa through Poseidon .

Alkione is a Be star of spectral class B5 and luminosity class IIIe. It also appears to be a slowly pulsating B star . As with most stars in the Pleiades, the exact distance is still relatively unclear. More recent measurements of the Gaia mission indicate a high error rate ( Gaia DR2 , error rate high due to the high brightness ) to a distance of about 410 light years, while the data from the Hipparcos mission initially indicated 370 LJ, but later to about 400 LJ upwards corrected.

The IAU Working Group on Star Names (WGSN) has the proper name on 30 June 2016 Alcyone defined as standardized proper name for this star.

Web links

Commons : Alkione  - collection of images, videos and audio files

Individual evidence

  1. a b c d e f g h eta Tau. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed January 27, 2019 .
  2. a b Y. Touhami, DR Gies, GH Schaefer, HA McAlister, ST Ridgway, ND Richardson, R. Matson, ED Grundstrom, TA Ten Brummelaar, PJ Goldfinger, L. Sturmann, J. Sturmann, NH Turner, C. Farrington : A CHARA Array Survey of Circumstellar Disks around Nearby Be-type Stars . In: The Astrophysical Journal . 768, No. 2, 2013, p. 128. arxiv : 1302.6135 . bibcode : 2013ApJ ... 768..128T . doi : 10.1088 / 0004-637X / 768/2/128 .
  3. J. Zorec, Y. Fremat, L. Cidale: On the evolutionary status of Be stars. I. Field Be stars near the Sun . In: Astronomy and Astrophysics . 441, 2005, p. 235. arxiv : astro-ph / 0509119 . bibcode : 2005A & A ... 441..235Z . doi : 10.1051 / 0004-6361: 20053051 .
  4. Jump up ↑ TR White, BJS Pope, V. Antoci, PI Pápics, C. Aerts, DR Gies, K. Gordon, D. Huber, GH Schaefer, S. Aigrain, S. Albrecht, T. Barclay, G. Barentsen, PG Beck , TR Bedding, M. Fredslund Andersen, F. Grundahl, SB Howell, MJ Ireland, SJ Murphy, MB Nielsen, V. Silva Aguirre, PG Tuthill: Beyond the Kepler / K2 bright limit: Variability in the seven brightest members of the Pleiades . In: Monthly Notices of the Royal Astronomical Society . 471, No. 3, 2017, pp. 2882–2901. arxiv : 1708.07462 . bibcode : 2017MNRAS.471.2882W . doi : 10.1093 / mnras / stx1050 .
  5. NSI 15775. In: VSX. AAVSO, accessed July 21, 2018 .
  6. ^ F. van Leeuwen: Validation of the new Hipparcos reduction . In: Astronomy and Astrophysics . 474, No. 2, 2007, pp. 653-664. arxiv : 0708.1752 . bibcode : 2007A & A ... 474..653V . doi : 10.1051 / 0004-6361: 20078357 . Vizier catalog entry
  7. Bulletin of the IAU Working Group on Star Names, No. 1, July 2016. (PDF) Retrieved November 9, 2016 (English, 184 KiB).