Eta Centauri
| Observation data Epoch J2000 Equinox J2000 |
|
|---|---|
| Constellation | Centaurus |
| Right ascension | 14h 35m 30.4s |
| Declination | −42° 09′ 28″ |
| Apparent magnitude (V) | +2.33 |
| Characteristics | |
| Spectral type | B1.5 Vne[1] |
| U−B color index | −0.83 |
| B−V color index | −0.19 |
| Variable type | Gamma Cas |
| Astrometry | |
| Radial velocity (Rv) | 0 km/s |
| Proper motion (μ) | RA: −35.31 mas/yr Dec.: −32.44 mas/yr |
| Parallax (π) | 10.57 ± 0.83 mas |
| Distance | 310 ± 20 ly (95 ± 7 pc) |
| Absolute magnitude (MV) | −2.54 |
| Details | |
| Mass | 12.0 ± 0.3[2] M☉ |
| Radius | 5-6 R☉ |
| Luminosity | 8,700[1] L☉ |
| Surface gravity (log g) | 3.20[3] |
| Temperature | 25,700[1] K |
| Rotational velocity (v sin i) | 330[1] km/s |
| Age | 5.6 ± 1.0[2] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Eta Centauri (η Cen, η Centauri) is a star in the constellation Centaurus.
It is a rapidly rotating star that completes a full rotation in less than a day. It is also a Be star,[4] which means it has variable emissions in its hydrogen spectral lines. Finally it is also slightly variable, and classified as a Gamma Cassiopeiae variable, with multiple periods of variability. It is approximately 309 light years from Earth. Eta Centauri is sufficiently large that it is on the dividing line between stars that evolve into white dwarfs and those that turn into supernovae.
This star is a proper motion member of the Upper-Centaurus Lupus sub-group in the Scorpius-Centaurus OB association, the nearest such co-moving association of massive stars to the Sun.[3]
In traditional Chinese astronomy, Eta Centauri was known as 庫樓二[5] (meaning: the Second (Star) of Koo Low).[6]
[edit] See also
[edit] References
- ^ a b c d Balona, L. A.; Dziembowski, W. A. (October 1999), "Excitation and visibility of high-degree modes in stars", Monthly Notices of the Royal Astronomical Society 309 (1): 221-232, Bibcode 1999MNRAS.309..221B, doi:10.1046/j.1365-8711.1999.02821.x
- ^ a b Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (january 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society 410 (1): 190–200, Bibcode 2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x
- ^ a b de Geus, P. T.; de Zeeuw; Lub, J. (June 1989), "Physical parameters of stars in the Scorpio-Centaurus OB association", Astronomy and Astrophysics 216 (1-2): 44–61, Bibcode 1989A&A...216...44D
- ^ Janot-Pacheco, E., Leister, N. V. et al. (1999), "Multi-periodicity of the Be star η Centauri from spectroscopic and photometric observations", A&AS 137 (3): 407, Bibcode 1999A&AS..137..407J, doi:10.1051/aas:1999256
- ^ (Chinese) 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, ISBN 978-986-7332-25-7.
- ^ Allen, R. H. (1963), Star Names: Their Lore and Meaning (rep. ed.), New York, NY: Dover Publications Inc., p. 154, ISBN 0486210790
[edit] External links
- Eta Centauri by Jim Kaler.
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