Epsilon Telescopii

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Epsilon Telescopii
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Telescopium
Right ascension 18h 11m 13.76324s[1]
Declination −45° 57′ 15.9029″[1]
Apparent magnitude (V) 4.53[2]
Spectral type K0 III[3]
U−B color index +0.78[2]
B−V color index +1.01[2]
Radial velocity (Rv) −26.3[4] km/s
Proper motion (μ) RA: −15.46[1] mas/yr
Dec.: −37.16[1] mas/yr
Parallax (π) 7.80 ± 0.59[1] mas
Distance 420 ± 30 ly
(128 ± 10 pc)
Luminosity 293[5] L
Surface gravity (log g) 2.32±0.12[6] cgs
Temperature 4,996±42[6] K
Metallicity [Fe/H] −0.07±0.04[6] dex
Other designations
ε Tel, CD−45° 12251, FK5 1473, HD 166063, HIP 89112, HR 6783, SAO 228777[7]
Database references

Epsilon Telescopii (ε Tel, ε Telescopii) is a solitary,[8] orange-hued star in the southern constellation of Telescopium. It is visible to the naked eye with an apparent visual magnitude of +4.53.[2] Based upon an annual parallax shift of 7.80 mas as seen from Earth,[1] it is located roughly 420 light years from the Sun, give or take 30 light years.

This an evolved K-type giant with a stellar classification of K0 III.[3] It display an infrared excess, suggesting the presence of an orbiting disk of dust.[9] The star is radiating 293[5] times the Sun's luminosity from its photosphere at an effective temperature of 4,996 K.[6] It has a 13th magnitude optical companion at an angular separation of 16.30 arcseconds along a position angle of 233°, as of 2000.[10]


  1. ^ a b c d e f van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, Bibcode:2007A&A...474..653V, arXiv:0708.1752Freely accessible, doi:10.1051/0004-6361:20078357. 
  2. ^ a b c d Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99), Bibcode:1966CoLPL...4...99J. 
  3. ^ a b Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, 2, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1978mcts.book.....H. 
  4. ^ Wilson, Ralph Elmer (1953), "General catalogue of stellar radial velocities", Washington, Carnegie Institution of Washington: 0, Bibcode:1953GCRV..C......0W. 
  5. ^ a b McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–57, Bibcode:2012MNRAS.427..343M, arXiv:1208.2037Freely accessible, doi:10.1111/j.1365-2966.2012.21873.x. 
  6. ^ a b c d Alves, S.; et al. (April 2015), "Determination of the spectroscopic stellar parameters for 257 field giant stars", Monthly Notices of the Royal Astronomical Society, 448 (3): 2749–2765, Bibcode:2015MNRAS.448.2749A, arXiv:1503.02556Freely accessible, doi:10.1093/mnras/stv189.  Per the comments in the paper, this lists the TS13 data.
  7. ^ "eps Tel – Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2017-06-07. 
  8. ^ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, Bibcode:2008MNRAS.389..869E, arXiv:0806.2878Freely accessible, doi:10.1111/j.1365-2966.2008.13596.x. 
  9. ^ Zuckerman, B.; et al. (June 1995), "Luminosity Class III Stars with Excess Far-Infrared Emission", Astrophysical Journal Letters, 446: L79, Bibcode:1995ApJ...446L..79Z, doi:10.1086/187935. 
  10. ^ Mason, B. D.; et al. (2014), The Washington Visual Double Star Catalog, Bibcode:2001AJ....122.3466M, doi:10.1086/323920, retrieved 2015-07-22