Alkiones (star)
Star Alkione (η Tauri) |
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Center left in the Pleiades: Alkione | |||||||||||||||||||||
AladinLite | |||||||||||||||||||||
Observation dates equinox : J2000.0 , epoch : J2000.0 |
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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 |
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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 |
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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
Individual evidence
- ↑ a b c d e f g h eta Tau. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed January 27, 2019 .
- ↑ 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 .
- ↑ 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 .
- 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 .
- ↑ NSI 15775. In: VSX. AAVSO, accessed July 21, 2018 .
- ^ 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
- ↑ Bulletin of the IAU Working Group on Star Names, No. 1, July 2016. (PDF) Retrieved November 9, 2016 (English, 184 KiB).