Delta Eridani
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Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Eridanus |
Right ascension | 03h 43m 14.90s[1] |
Declination | –09° 45′ 48.2″[1] |
Apparent magnitude (V) | 3.54[2] |
Characteristics | |
Spectral type | K0 IV[3] |
U−B color index | +0.69[4] |
B−V color index | +0.92[4] |
Variable type | Suspected |
Astrometry | |
Radial velocity (Rv) | –6.28 ± 0.09[5] km/s |
Proper motion (μ) | RA: –93.16 ± 0.29[1] mas/yr Dec.: +743.64 ± 0.22[1] mas/yr |
Parallax (π) | 110.61 ± 0.29[1] mas |
Distance | 29.49 ± 0.08 ly (9.04 ± 0.02 pc) |
Absolute magnitude (MV) | 3.77[6] |
Details | |
Mass | 1.33 ± 0.07[7] M☉ |
Radius | 2.327 ± 0.029[7] R☉ |
Luminosity | 3.00 ± 0.12[7] L☉ |
Surface gravity (log g) | 3.9[8] cgs |
Temperature | 5,055[9] K |
Metallicity [Fe/H] | 0.13[9] dex |
Rotational velocity (v sin i) | 1.0[6] km/s |
Other designations | |
Database references | |
SIMBAD | data |
Delta Eridani (δ Eri, δ Eridani) is a 3.54 magnitude star in the constellation of Eridanus.
Structure
This star is relatively near to the Sun, at a measured distance of about 29 light years. It is sometime listed as a RS Canum Venaticorum-type variable star, but this is likely to be an error. It is a suspected variable. δ Eridani is a subgiant star that has exhausted its core hydrogen. This has caused the star to expand and become cooler than a comparable main sequence star.
Etymology
In Chinese, 天苑 (Tiān Yuàn), meaning Celestial Meadows, refers to an asterism consisting of δ Eridani, γ Eridani, π Eridani, ε Eridani, ζ Eridani, η Eridani, π Ceti, τ1 Eridani, τ2 Eridani, τ3 Eridani, τ4 Eridani, τ5 Eridani, τ6 Eridani, τ7 Eridani, τ8 Eridani and τ9 Eridani.[10] Consequently, δ Eridani itself is known as 天苑三 (Tiān Yuàn sān, English: the Third Star of Celestial Meadows.)[11]
See also
References
- 1 2 3 4 5 van Leeuwen, F. (2007). "HIP 17378". Hipparcos, the New Reduction. Retrieved 2009-12-11.
- ↑ Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237. Bibcode:2002yCat.2237....0D.
- ↑ Spinrad, Hyron; Taylor, Benjamin J. (1969). "Scanner Abundance Studies. I. an Investigation of Supermetallicity in Late-Type Evolved Stars". Astrophysical Journal. 157: 1279. Bibcode:1969ApJ...157.1279S. doi:10.1086/150154.
- 1 2 Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Bibcode:1986EgUBV........0M.
- ↑ Jofré, E.; Petrucci, R.; Saffe, C.; Saker, L.; de la Villarmois, E. Artur; Chavero, C.; Gómez, M.; Mauas, P. J. D. (2015). "Stellar parameters and chemical abundances of 223 evolved stars with and without planets". Astronomy & Astrophysics. 574. arXiv:1410.6422. Bibcode:2015A&A...574A..50J. doi:10.1051/0004-6361/201424474.
- 1 2 Pizzolato, N.; Maggio, A.; Sciortino, S. (September 2000), "Evolution of X-ray activity of 1-3 Msun late-type stars in early post-main-sequence phases", Astronomy and Astrophysics, 361: 614–628, Bibcode:2000A&A...361..614P
- 1 2 3 Bruntt, H.; et al. (July 2010), "Accurate fundamental parameters for 23 bright solar-type stars", Monthly Notices of the Royal Astronomical Society, 405 (3): 1907–1923, arXiv:1002.4268, Bibcode:2010MNRAS.405.1907B, doi:10.1111/j.1365-2966.2010.16575.x
- ↑ Morell, O.; Kallander, D.; Butcher, H. R (1999). "The age of the Galaxy from thorium in G dwarfs, a re-analysis". Astronomy and Astrophysics. 259 (2): 543–548. Bibcode:1992A&A...259..543M.
- 1 2 Piau, L.; et al. (February 2011), "Surface convection and red-giant radius measurements", Astronomy and Astrophysics, 526: A100, arXiv:1010.3649, Bibcode:2011A&A...526A.100P, doi:10.1051/0004-6361/201014442
- ↑ (in 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.
- ↑ (in Chinese) 香港太空館 - 研究資源 - 亮星中英對照表 Archived January 30, 2011, at the Wayback Machine., Hong Kong Space Museum. Accessed on line November 23, 2010.
Sources
- Fisher, G. F., Hall, D. S., Henry, G. W., Landis, H. J., Renner, T. R., and Shore, S. N., "Delta Eridani: A Very Bright New Variable Star,", Information Bulletin on Variable Stars, No. 2259, 1983.
- Eaton, J. A.; Poe, C. H., "Limits on the Variability of epsilon Eridani and delta Eridani", Information Bulletin on Variable Stars, 2712, 1985.
External links
- Jim Kaler's page on Rana
- SolStation entry
- nStars entry