Eta Eridani
Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Eridanus |
Right ascension | 02h 56m 25.64948s[1] |
Declination | −08° 53′ 53.3221″[1] |
Apparent magnitude (V) | +3.87[2] |
Characteristics | |
Spectral type | K1+ IIIb[3] |
U−B color index | _0.98[2] |
B−V color index | +1.12[2] |
Variable type | suspected[4] |
Astrometry | |
Radial velocity (Rv) | −20.32 km/s |
Proper motion ( | RA: +77.36 ± 0.19[1] mas/yr Dec.: −220.16 ± 0.20[1] mas/yr |
Parallax ( | 23.89 ± 0.19 mas[1] |
Distance | 137 ± 1 ly (41.9 ± 0.3 pc) |
Absolute magnitude (MV) | +0.83[5] |
Details | |
Mass | 1.43[6] M☉ |
Radius | 10.48[6] R☉ |
Luminosity | 57.5[6] L☉ |
Surface gravity (log g) | +2.79[6] cgs |
Temperature | 4,742[6] K |
Rotational velocity (v sin i) | 2.34[6] km/s |
Age | 2.66[6] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
Eta Eridani (
Nomenclature
It bore the traditional name Azha, from the old Arab asterism نَعَام أُدْحِيّ udḥiyy al-naʽām "the ostrich nest" (or "hatching place"), which included Eta Eridani.[9] The first word, ادحى udḥiyy, was miscopied as ازحى (readable as azḥā) in medieval manuscripts.[8] In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN)[10] to catalogue and standardize proper names for stars. The WGSN approved the name Azha for this star on 12 September 2016 and it is now so included in the List of IAU-approved Star Names.[7]
In Chinese,
Properties
References
- ^ a b c d e Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.
- ^ a b c 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: 0. Bibcode:2002yCat.2237....0D.
- ^ Keenan, Philip C.; McNeil, Raymond C. (1989). "The Perkins catalog of revised MK types for the cooler stars". Astrophysical Journal Supplement Series. 71: 245. Bibcode:1989ApJS...71..245K. doi:10.1086/191373.
- ^ a b Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/gcvs. Originally Published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.
- ^ Da Silva, L.; Girardi, L.; Pasquini, L.; Setiawan, J.; von Der Lühe, O.; De Medeiros, J. R.; Hatzes, A.; Döllinger, M. P.; Weiss, A. (2006). "Basic physical parameters of a selected sample of evolved stars". Astronomy and Astrophysics. 458 (2): 609. arXiv:astro-ph/0608160. Bibcode:2006A&A...458..609D. doi:10.1051/0004-6361:20065105.
- ^ a b c d e f g 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: A50. arXiv:1410.6422. Bibcode:2015A&A...574A..50J. doi:10.1051/0004-6361/201424474.
- ^ a b c "Naming Stars". IAU.org. Retrieved 16 December 2017.
- ^ a b Davis, George A. (1944). "The pronunciations, derivations, and meanings of a selected list of star names". Popular Astronomy. 52: 8–30.
- ^ Kunitzsch, Paul; Smart, Tim (2006). A Dictionary of Modern star Names: A Short Guide to 254 Star Names and Their Derivations (2nd rev. ed.). Cambridge, Massachusetts: Sky Pub. ISBN 978-1-931559-44-7.
- ^ IAU Working Group on Star Names (WGSN), International Astronomical Union, retrieved 22 May 2016.
- ^ (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 August 11, 2010, at the Wayback Machine, Hong Kong Space Museum. Accessed on line November 23, 2010. - ^ Laney, C. D.; Joner, M. D.; Pietrzyński, G. (2012). "A new Large Magellanic Cloud K-band distance from precision measurements of nearby red clump stars". Monthly Notices of the Royal Astronomical Society. 419 (2): 1637. arXiv:1109.4800. Bibcode:2012MNRAS.419.1637L. doi:10.1111/j.1365-2966.2011.19826.x.
- ^ Lu, Phillip K. (1991). "Taxonomy of barium stars". Astronomical Journal. 101: 2229. Bibcode:1991AJ....101.2229L. doi:10.1086/115845.
- ^ Gontcharov, G. A.; Andronova, A. A.; Titov, O. A.; Kornilov, E. V. (2001). "The proper motions of fundamental stars. I. 1535 stars from the Basic FK5". Astronomy and Astrophysics. 365 (2): 222. Bibcode:2001A&A...365..222G. doi:10.1051/0004-6361:20000010.