Epsilon Draconis

Epsilon Draconis
Location of ε Draconis (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Draco
Right ascension 19h 48m 10.34973s[1]
Declination 70° 16′ 04.5329″[1]
Apparent magnitude (V) 3.9974[2]
Characteristics
Spectral type G7IIIbFe-1[3]
U−B color index +0.48[4]
B−V color index +0.88 [4]
Astrometry
Radial velocity (Rv)+2.69±0.23[5] km/s
Proper motion (μ) RA: +79.702[1] mas/yr
Dec.: +41.078[1] mas/yr
Parallax (π)21.2526 ± 0.3016 mas[1]
Distance153 ± 2 ly
(47.1 ± 0.7 pc)
Absolute magnitude (MV)0.71[2]
Details
Mass2.7[6][7] M☉
Radius11.15+0.47
−0.56[1] R☉
Luminosity69.6±1.12[1] L☉
Temperature4993+129
−103[1] K
Metallicity [Fe/H]-0.31[8] dex
Rotational velocity (v sin i)1.2 [6] km/s
Age500[6] Myr
Other designations
Tyl, ε Dra, 63 Dra, AG+70° 689, BD+69° 1070, GC 27471, HD 188119, HIP 97433, HR 7582, SAO 9540, CCDM J19482+7016AB, PLX 4689, IRAS 19483+7008, 2MASS J19481035+7016045[9]
Database references
SIMBADdata

Epsilon Draconis, Latinized from ε Draconis, is a fourth-magnitude star in the constellation Draco. This star along with Delta Draconis (Altais), Pi Draconis and Rho Draconis forms an asterism known as Al Tāis, meaning "the Goat".[10]

In Chinese astronomy, 天廚 (Tiān Chú), meaning the Celestial Kitchen, refers to an asterism consisting of Epsilon Draconis, Delta Draconis, Sigma Draconis, Rho Draconis, 64 Draconis and Pi Draconis.[11] Consequently, the Chinese name for Epsilon Draconis itself is 天廚三 (Tiān Chú sān, English: the Third Star of the Celestial Kitchen.)[12] Most authors do not use a traditional name for this star, using instead the Bayer designation;[13] but Bečvář (1951) listed it as Tyl /ˈtɪl/.[14][15]

  1. ^ a b c d e f g h Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  2. ^ a b van Leeuwen, F (November 2007). "Hipparcos, the New Reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID 18759600. Retrieved 2010-12-18.
  3. ^ 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.
  4. ^ a b Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. SIMBAD. Bibcode:1986EgUBV........0M.
  5. ^ Soubiran, C.; et al. (2008). "Vertical distribution of Galactic disk stars. IV. AMR and AVR from clump giants". Astronomy and Astrophysics. 480 (1): 91–101. arXiv:0712.1370. Bibcode:2008A&A...480...91S. doi:10.1051/0004-6361:20078788. S2CID 16602121.
  6. ^ a b c Mallik, Sushma V.; Parthasarathy, M.; Pati, A. K. (October 2003). "Li abundances and velocities in F and G stars". VizieR. Centre de Données astronomiques de Strasbourg. Retrieved 2010-12-18.
  7. ^ Mallik, Sushma V.; Parthasarathy, M.; Pati, A. K. (October 2003). "Lithium and rotation in F and G dwarfs and subgiants". Astronomy and Astrophysics. 409 (1): 251–261. Bibcode:2003A&A...409..251M. doi:10.1051/0004-6361:20031084. Retrieved 2010-12-18.
  8. ^ Soubiran, C.; Bienaymé, O.; Mishenina, T. V.; Kovtyukh, V. V. (2008). "Vertical distribution of Galactic disk stars. IV. AMR and AVR from clump giants". Astronomy and Astrophysics. 480 (1): 91–101. arXiv:0712.1370. Bibcode:2008A&A...480...91S. doi:10.1051/0004-6361:20078788. S2CID 16602121.
  9. ^ "* eps Dra". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2010-12-18.
  10. ^ Allen, R. H. (1963). Star Names: Their Lore and Meaning (Reprint ed.). New York, NY: Dover Publications Inc. p. 209. ISBN 0-486-21079-0. Retrieved 2010-12-12.
  11. ^ (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.
  12. ^ (in Chinese) 香港太空館 - 研究資源 - 亮星中英對照表 Archived August 19, 2010, at the Wayback Machine, Hong Kong Space Museum. Accessed on line November 23, 2010.
  13. ^ Kaler, Jim. "Epsilon Draconis". Retrieved 2016-11-24.
  14. ^ 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.
  15. ^ Bakich, Michael (1995). The Cambridge Guide to the Constellations. Cambridge University Press. p. 202. ISBN 0521449219. Retrieved 2016-11-24. Tyl.