Epoch J2000 Equinox J2000
|Right ascension||17h 21m 59.47633s|
|Declination||−67° 46′ 14.4072″|
|Apparent magnitude (V)||+4.78|
|Spectral type||K2 III|
|U−B color index||+1.27|
|B−V color index||+1.21|
|Radial velocity (Rv)||+12.6 km/s|
|Proper motion (μ)||RA: –37.85 mas/yr
Dec.: –7.91 mas/yr
|Parallax (π)||10.97 ± 0.29 mas|
|Distance||297 ± 8 ly
(91 ± 2 pc)
Zeta Apodis (ζ Aps, ζ Apodis) is the Bayer designation for a star in the southern constellation of Apus. It has an apparent visual magnitude of +4.78, which is bright enough to allow it to be seen with the naked eye. The distance to this star is known from parallax measurements to be around 297 light-years (91 parsecs).
The spectrum of Zeta Apodis matches a stellar classification of K2 III, with the luminosity class of III indicating it is an evolved giant star. The measured angular diameter of this star, after correction for limb darkening, is 2.06 ± 0.02 mas. At the estimated distance of Eta Draconis, this yields a physical size of about 11 times the radius of the Sun. The outer atmosphere has an effective temperature of 4,388 K, which gives it the orange-hued glow of a K-type star.
In Chinese caused by adaptation of the European southern hemisphere constellations into the Chinese system, 異雀 (Yì Què), meaning Exotic Bird, refers to an asterism consisting of ζ Apodis, ι Apodis, β Apodis, γ Apodis, δ Octantis, δ1 Apodis, η Apodis, α Apodis and ε Apodis. Consequently, ζ Apodis itself is known as 異雀一 (Yì Què yī, English: the First Star of Exotic Bird.)
- van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357.
- 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.
- Houk, Nancy; Cowley, A. P. (1978), Michigan catalogue of two-dimensional spectral types for the HD stars 1, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1975mcts.book.....H.
- Wilson, R. E. (1953), General Catalogue of Stellar Radial Velocities, Carnegie Institute of Washington D.C., Bibcode:1953GCRV..C......0W.
- Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library 1 (3rd ed.), Birkhäuser, ISBN 3-540-29692-1.. The radius (R*) is given by:
- di Benedetto, G. P. (November 1998), "Towards a fundamental calibration of stellar parameters of A, F, G, K dwarfs and giants", Astronomy and Astrophysics 339: 858–871, Bibcode:1998A&A...339..858D.
- "zet Aps -- Star", SIMBAD Astronomical Object Database (Centre de Données astronomiques de Strasbourg), retrieved 2012-02-04
- Richichi, A.; Percheron, I.; Khristoforova, M. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics 431: 773–777, Bibcode:2005A&A...431..773R, doi:10.1051/0004-6361:20042039.
- "The Colour of Stars", Australia Telescope, Outreach and Education (Commonwealth Scientific and Industrial Research Organisation), December 21, 2004, retrieved 2012-01-16.
- (Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 29 日