- Delta Eridani
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δ Eridani Observation data
Epoch J2000 Equinox J2000Constellation Eridanus Right ascension 03h 43m 14.90s [1] Declination –09° 45′ 48.2″ [1] Apparent magnitude (V) 3.54 Characteristics Spectral type K0 IV U−B color index 0.69 B−V color index 0.92 Variable type Suspected Astrometry Radial velocity (Rv) -6 km/s Proper motion (μ) RA: -93.16 ± 0.29 [1] mas/yr
Dec.: 743.64 ± 0.22 [1] mas/yrParallax (π) 110.61 ± 0.29[1] mas Distance 29.49 ± 0.08 ly
(9.04 ± 0.02 pc)Absolute magnitude (MV) 3.75 Details Mass 1.2 M☉ Radius 2.3-2.7 R☉ Surface gravity (log g) 3.9[2]/– rotation=116 days Luminosity 2.8 L☉ Temperature 5,075 K Metallicity 150% Sun Age 7.5 × 109 years Other designations Delta Eridani (δ Eri, δ Eridani) is a 3.54 magnitude star in the constellation of Eridanus. It is also called Rana. The name Rana means "the frog" in Latin[3]
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, edit] 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 currently a suspected variable.) Rana is a sub-giant star that is near the end of its hydrogen-burning cycle and is now consuming helium. This has caused the star to expand and become hotter than a comparable main sequence star. As a sub-giant star it is subject to pulsations in its atmosphere.
Radial velocity surveys of this star have thus far failed to discern any gas giants in orbit.
References
- ^ a b c d e van Leeuwen, F. (2007). "HIP 17378". Hipparcos, the New Reduction. http://webviz.u-strasbg.fr/viz-bin/VizieR-5?-out.add=.&-source=I/311/hip2&recno=17335. Retrieved 2009-12-11.
- ^ 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.
- ^ Constellations of Words - Eridanus (Rana)
- ^ (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.
- ^ (Chinese) 香港太空館 - 研究資源 - 亮星中英對照表, Hong Kong Space Museum. Accessed on line November 23, 2010.
- 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
Star systems (including brown dwarf systems) within 25–30 light-years from Earth. Pi³ Orionis «Tabit» (26.2 ± 0.2 ly; 1 star) • Chi Draconis (26.22 ± 0.11 ly; 2 stars) • Zeta Tucanae (28.0 ± 0.2 ly; 1 star) • Gamma Leporis (29.3 ± 0.2 ly; 2 stars) • Gamma Pavonis (30.1 ± 0.2 ly; 1 star)‡Mu Herculis (27.4 ± 0.2 ly; 3 stars)Xi Ursae Majoris «Alula Australis» (27.25 ± 0.18 ly; 3 stars, 1 brown dwarf) • Beta Canum Venaticorum «Chara» (27.3 ± 0.2 ly; 1 star) • 61 Virginis (27.8 ± 0.2 ly; 1 star, 3 planets: planet b • planet c • planet d) • Chi¹ Orionis (28.3 ± 0.3 ly; 2 stars) • 41 G. Arae (28.7 ± 0.3 ly; 2 stars) • Beta Comae Berenices (29.9 ± 0.2 ly; 1 star)‡ • Kappa¹ Ceti (29.9 ± 0.2 ly; 1 star)‡ • HR 4523 (30.1 ± 0.2 ly; 2 stars, 1 planet: planet b)‡Groombridge 1830 (29.9 ± 0.2 ly; 1 star)‡Delta Eridani «Rana» (29.5 ± 0.3 ly; 1 star)TW Piscis Austrini (24.9 ± 0.2 ly; 1 star)‡ • Gliese 673 (25.2 ± 0.2 ly; 1 star)‡ • Gliese 884 (26.6 ± 0.3 ly; 1 star) • p Eridani (26.6 ± 0.3 ly; 2 stars) • Gliese 250 (28.4 ± 0.3 ly; 2 stars) • HR 1614 (28.8 ± 0.3 ly; 1 star) • HR 7722 (28.8 ± 0.3 ly; 1 star, 2 planets: planet b • planet c)Gliese 623 (26.2 ± 0.3 ly; 2 stars) • AP Columbae (27.4 ± 0.2 ly; 1 star) • Gliese 185 (27.8 ± 0.4 ly; 2 stars) • Gliese 745 (28.1 ± 0.6 ly; 2 stars) • Gliese 849 (28.6 ± 0.5 ly; 1 star, 1 planet: planet b) • Gliese 433 (29.5 ± 0.5 ly; 1 star, 1 planet: planet b) • Gliese 317 (29.9 ± 5.5 ly; 1 star: Gliese 317; 1 (2?) planets: planet b • planet c?)‡DAGJ 1087 (26.1 ± 0.8 ly; 1 star) • Gliese 915 (26.7 ± 0.3 ly; 1 star) • Gliese 318 (28.7 ± 0.5 ly; 1 star)DCGliese 293 (25.8 ± 0.3 ly; 1 star)DQGJ 2012 (29.5 ± 0.3 ly; 1 star)DZGliese 518 (26.9 ± 0.8 ly; 1 star) • GJ 1276 (27.9 ± 0.2 ly; 1 star) • Gliese 283 (29.7 ± 0.2 ly; 2 stars)SDSS J1416+13 (25.7 ± 5.5 ly; 2 brown dwarfs)‡ • WISE 1647+5632 (28.1 + 9.4/- 5.6 ly; 1 brown dwarf)‡ • 2MASS 0036+1821 (28.6 ± 0.2 ly; 1 brown dwarf)WISE 0254+0223 (19.8 + 7.6/- 4.3 ly; 1 brown dwarf)‡ • WISE 0313+7807 (~26.4 ly; 1 brown dwarf)‡ • UGPS J0521+3640 (26.7 + 3.9/- 3.2 ly; 1 brown dwarf)‡ • 2MASS 0727+1710 (29.6 ± 0.6 ly; 1 brown dwarf)‡ • CFBDS J005910.90-011401.3 (30.1 + 1.5/- 1.3 ly; 1 brown dwarf)‡ • WISE 2313-8037 (30.3 ± 1.3 ly; 1 brown dwarf)‡ • WISE 0458+6434 (34.2 ± 4.6 ly; 2 brown dwarfs)‡WISE 0410+1502 (23.2 + 5.2/- 12.7 ly; 1 brown dwarf)‡In left column are stellar classes of primary members of star systems. ‡Distance error margin extends out of declared distance interval. Bold are systems containing at least one component with absolute magnitude of +8.5 or brighter. Italic are systems possibly located within declared distance interval, but probably not. Nearest bright star systems Star systems within 30 light-years from Earth with brightest member's absolute magnitude of +8.5 or brighter. 0–10 ly → Sirius (8.58 ± 0.03 ly; 2 stars)Solar System (0 ly; 1 star, 8 planets) • Alpha Centauri (4.365 ± 0.007 ly; 3 stars: Alpha¹ Centauri • Alpha² Centauri • Proxima Centauri (4.242 ± 0.002 ly))Altair (16.69 ± 0.04 ly; 1 star)Procyon (11.44 ± 0.02 ly; 2 stars)Tau Ceti (11.905 ± 0.007 ly; 1 star) • Sigma Draconis «Alsafi» (18.77 ± 0.02 ly; 1 star) • Eta Cassiopeiae «Achird» (19.39 ± 0.05 ly; 2 stars) • e (82 G.) Eridani (19.71 ± 0.02 ly; 1 star, 3 planets: planet b • planet c • planet d) • Delta Pavonis (19.92 ± 0.02 ly; 1 star)Epsilon Eridani (10.480 ± 0.003 ly; 1 star, 2 planets: planet b • planet c) • 61 Cygni (11.40 ± 0.02 ly; 2 stars) • Epsilon Indi (11.81 ± 0.01 ly; 1 star, 2 brown dwarfs) • Groombridge 1618 (15.87 ± 0.04 ly; 1 star) • Omicron² (40) Eridani «Keid» (16.25 ± 0.02 ly; 3 stars) • 70 Ophiuchi (16.64 ± 0.07 ly; 2 stars) • 33 G. Librae (19.12 ± 0.08 ly; 3 stars, 1 brown dwarf) • 36 Ophiuchi (19.40 ± 0.05 ly; 3 stars) • Gliese 783 (19.62 ± 0.04 ly; 2 stars)Pi³ Orionis «Tabit» (26.2 ± 0.2 ly; 1 star) • Chi Draconis (26.22 ± 0.11 ly; 2 stars) • Zeta Tucanae (28.0 ± 0.2 ly; 1 star) • Gamma Leporis (29.3 ± 0.2 ly; 2 stars) • Gamma Pavonis (30.1 ± 0.2 ly; 1 star)‡Beta Hydri (24.4 ± 0.1 ly; 1 star) • Mu Herculis (27.4 ± 0.2 ly; 3 stars)Xi Boötis (22.1 ± 0.2 ly; 2 stars) • Xi Ursae Majoris «Alula Australis» (27.25 ± 0.18 ly; 3 stars, 1 brown dwarf) • Beta Canum Venaticorum «Chara» (27.3 ± 0.2 ly; 1 star) • 61 Virginis (27.8 ± 0.2 ly; 1 star, 3 planets: planet b • planet c • planet d) • Chi¹ Orionis (28.3 ± 0.3 ly; 2 stars) • 41 G. Arae (28.7 ± 0.3 ly; 2 stars) • Beta Comae Berenices (29.9 ± 0.2 ly; 1 star)‡ • Kappa¹ Ceti (29.9 ± 0.2 ly; 1 star)‡ • HR 4523 (30.1 ± 0.2 ly; 2 stars, 1 planet: planet b)‡Mu Cassiopeiae «Marfak-West» (24.6 ± 0.2 ly; 2 stars) • Groombridge 1830 (29.9 ± 0.2 ly; 1 star)‡Delta Eridani «Rana» (29.5 ± 0.3 ly; 1 star)Gliese 892 (21.34 ± 0.04 ly; 1 star) • HR 753 (23.5 ± 0.2 ly; 3 stars) • Gliese 667 (23.6 ± 0.1 ly; 3 stars, 1 planet: planet Cb) • Gliese 33 (24.3 ± 0.2 ly; 1 star) • 107 Piscium (24.4 ± 0.2 ly; 1 star) • TW Piscis Austrini (24.9 ± 0.2 ly; 1 star) • Gliese 673 (25.2 ± 0.2 ly; 1 star) • Gliese 884 (26.6 ± 0.3 ly; 1 star) • p Eridani (26.6 ± 0.3 ly; 2 stars) • Gliese 250 (28.4 ± 0.3 ly; 2 stars) • HR 1614 (28.8 ± 0.3 ly; 1 star) • HR 7722 (28.8 ± 0.3 ly; 1 star, 2 planets: planet b • planet c)In left column are stellar classes of primary members of star systems. ‡Distance error margin extends out of declared distance interval. Italic are systems possibly located within declared distance interval, but likely not. Total about 50 (47–52) systems. Bayer α (Achernar) • β (Cursa) • γ (Zaurak) • δ (Rana) • ε • ζ (Zibal) • η (Azha) • θ (Acamar) • ι • κ • λ • μ • ν • ξ • ο¹ (Beid) • ο² (Keid) • π • ρ¹ (rho-1) • ρ² (rho-2) • ρ³ (rho-3) • τ¹ • τ² (Angetenar) • τ³ • τ4 • υ¹ (Theemin) • υ² (Beemin) • υ³ • φ • χ • ψ • ω • b • c • d • e (82 G.) • f • g • h • i • l (Sceptrum) • p • q¹ • q² • s • v • w • y • AFlamsteed 1 (τ¹) • 2 (τ², Angetenar) • 3 (η, Azha) • 4 • 5 • 6 • 7 • 8 (ρ¹, rho-1) • 9 (ρ², rho-2) • 10 (ρ³, rho-3) • 11 (τ<³) • 13 (ζ, Zibal) • 14 • 15 • 16 (τ4) • 17 • 18 (ε) • 20 • 21 • 22 • 23 (δ, Rana) • 24 • 25 • 26 (π) • 29 • 30 • 32 (w) • 34 (γ, Zaurak) • 35 • 37 • 38 (ο¹, Beid) • 39 (A) • 40 (ο², Keid) • 42 (ξ) • 45 • 46 • 47 • 48 (ν) • 50 (υ¹, Theemin) • 51 (c) • 52 (υ², Beemin) • 53 (l, Sceptrum) • 54 • 55 • 56 • 57 (μ) • 58 • 59 • 60 • 61 (ω) • 62 (b) • 63 • 64 • 65 (ψ) • 66 • 67 (β, Cursa) • 68 • 69 (λ)Nearby ε • DEN 0255-4700 • ο² (Keid) • LHS 1723 • 2MASS 0415-0935 • e (82 G.) • LP 771-095 • p • LP 655-48 • HR 1614 • δ (Rana)List Categories:- Bayer objects
- Eridanus constellation
- K-type subgiants
- Stars with proper names
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