Eta Capricorni
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Capricornus |
| Right ascension | 21h 04m 24.301s[1] |
| Declination | –19° 51′ 17.97″[1] |
| Apparent magnitude (V) | +4.82 |
| Characteristics | |
| Spectral type | A4V + F7/8V[2] |
| Astrometry | |
| Proper motion (μ) | RA: –37.62 ± 0.90[1] mas/yr Dec.: –24.95 ± 0.88[1] mas/yr |
| Parallax (π) | 19.49 ± 0.29[2] mas |
| Distance | 167 ± 2 ly (51.3 ± 0.8 pc) |
| Details | |
| Other designations | |
Eta Capricorni (η Cap, η Capricorni) is a binary star in the constellation Capricornus. It is approximately 167 light years from Earth.
The primary component, η Capricorni A, is a white A-type main sequence dwarf with an apparent magnitude of +4.82. Its companion, η Capricorni B, has an apparent magnitude of +6.5 and is located 0.34 arcseconds from the primary.
Sometimes, this star is called by the name Armus.[4]
Chinese Name
In Chinese, 十二國 (Shíer Guó), meaning Twelve States, refers to an asterism which is represent twelve ancient states in the Spring and Autumn Period and the Warring States period, consisting of η Capricorni, φ Capricorni, ι Capricorni, 38 Capricorni, 35 Capricorni, 36 Capricorni, χ Capricorni, θ Capricorni, 30 Capricorni, 33 Capricorni, ζ Capricorni, 19 Capricorni, 26 Capricorni, 27 Capricorni, 20 Capricorni and 21 Capricorni.[5] Consequently, η Capricorni itself is known as 周一 (Zhou yī, English: the First Star of Zhou), meaning that this star (together with 21 Capricorni and β Serpentis in Right Wall of Heavenly Market Enclosure (asterism)[6]) represent Zhou (周) (possibly Chow, the dynasty in China).[7]
References
- 1 2 3 4 van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. Vizier catalog entry
- 1 2 Docobo, J. A.; Andrade, M. (2013). "Dynamical and physical properties of 22 binaries discovered by W. S. Finsen". Monthly Notices of the Royal Astronomical Society 428 (1): 321–339. Bibcode:2013MNRAS.428..321D. doi:10.1093/mnras/sts045.
- ↑ "* eta Cap -- Double or multiple star". SIMBAD Astronomical Database. Centre de données astronomiques de Strasbourg. Retrieved 2014-12-31.
- ↑ http://www.constellationsofwords.com/stars/Armus.html
- ↑ (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.
- ↑ Richard Hinckley Allen: Star Names — Their Lore and Meaning: Serpens
- ↑ Richard Hinckley Allen: Star Names — Their Lore and Meaning: Capricornus
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