Upsilon2 Eridani

υ2 Eridani
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Eridanus
Right ascension 04h 35m 33.0385s[1]
Declination −30° 33′ 44.429″[1]
Apparent magnitude (V) 3.817[1]
Characteristics
Spectral type G8IIIa[1]
U−B color index +0.72[2]
B−V color index +0.98[2]
R−I color index +0.49[2]
Astrometry
Radial velocity (Rv)−4.0 ± 0.9[1] km/s
Proper motion (μ) RA: −48.92[1] mas/yr
Dec.: −12.75[1] mas/yr
Parallax (π)15.62 ± 0.63[1] mas
Distance209 ± 8 ly
(64 ± 3 pc)
Absolute magnitude (MV)0.91 ± 0.07[3]
Details
Mass1.38 ± 0.19[3] M☉
Radius11.4 ± 0.6[3] R☉
Surface gravity (log g)2.43 ± 0.09[3] cgs
Temperature4522[3] K
Metallicity [Fe/H]+0.24[3] dex
Age3.12 ± 1.15[3] Gyr
Other designations
Theemim, Theemin, Beemin, υ2 Eri, Upsilon2 Eridani, Upsilon2 Eri, 52 Eridani, 52 Eri, CD −30° 1901, CPD−30 631, FK5 170, GC 5614, HD 29291, HIP 21393, HR 1464, PPM 280424, SAO 195148.[1][2][4]
Database references
SIMBADdata

Upsilon2 Eridani (Upsilon2 Eri, υ2 Eridani, υ2 Eri) is a G-type giant star in the constellation of Eridanus.[1] It has an apparent visual magnitude of approximately 3.817 and is approximately 209 light-years from the Earth.[1] It also has the names Theemim (also Theemin) and Beemin.[2][4]

In Chinese, 天園 (Tiān Yuán), meaning Celestial Orchard, refers to an asterism consisting of υ2 Eridani, χ Eridani, φ Eridani, κ Eridani, HD 16754, HD 23319, θ Eridani, HD 24072, HD 24160, υ4 Eridani, 43 Eridani and υ1 Eridani.[5] Consequently, υ2 Eridani itself is known as 天園十二 (Tiān Yuán shíèr, English: the Twelfth Star of Celestial Orchard.)[6]

References

  1. 1 2 3 4 5 6 7 8 9 10 11 * 52 Eri -- Star, database entry, SIMBAD. Accessed on line September 25, 2008.
  2. 1 2 3 4 5 HR 1464, database entry, The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version), D. Hoffleit and W. H. Warren, Jr., CDS ID V/50. Accessed on line September 25, 2008.
  3. 1 2 3 4 5 6 7 da Silva, L.; et al. (November 2006), "Basic physical parameters of a selected sample of evolved stars", Astronomy and Astrophysics 458 (2): 609–623, arXiv:astro-ph/0608160, Bibcode:2006A&A...458..609D, doi:10.1051/0004-6361:20065105
  4. 1 2 p. 123, The Cambridge Guide to the Constellations, Michael E. Bakich, Cambridge University Press, 1995, ISBN 0-521-44921-9.
  5. ↑ (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.
  6. ↑ (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.


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