Epoch J2000 Equinox J2000
|Right ascension||14h 22m 23.16467s|
|Declination||–80° 06′ 32.2053″|
|Apparent magnitude (V)||5.06|
|Spectral type||B3 V|
|U−B color index||–0.610|
|B−V color index||–0.121|
|Variable type||γ Cas|
|Radial velocity (Rv)||+4.5 km/s|
|Proper motion (μ)||RA: –9.51 mas/yr
Dec.: –14.34 mas/yr
|Parallax (π)||5.06 ± 0.22 mas|
|Distance||640 ± 30 ly
(198 ± 9 pc)
|Mass||6.15 ± 0.71 M☉|
|Surface gravity (log g)||4.18 cgs|
|Metallicity [Fe/H]||–0.02 dex|
|Rotational velocity (v sin i)||255 km/s|
|Age||38.3 ± 4.4 Myr|
Epsilon Apodis (ε Aps, ε Apodis) is the Bayer designation for a star in the southern circumpolar constellation of Apus. It has an apparent visual magnitude of 5.06, which is bright enough to be viewed from dark suburban skies. Based upon parallax measurements, it is at a distance of roughly 640 light-years (200 parsecs) from Earth.
Based upon a stellar classification of B3 V, this is a massive, B-type main sequence star that is generating energy through the fusion of hydrogen at its core. Epsilon Apodis has more than six times the mass of the Sun and nearly four times the Sun's radius. It is radiating 1,614 times as much luminosity as the Sun from its outer envelope at an effective temperature of 17,050 K. At this heat, it has a blue-white glow that is a characteristic of B-type stars.
It is spinning rapidly, with a projected rotational velocity of 255 km/s  giving a lower bound for the azimuthal velocity along the equator. Epsilon Apodis is classified as a Gamma Cassiopeiae type variable star and its brightness varies between magnitudes 4.99 and 5.04.
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 ε Apodis, ζ Apodis, ι Apodis, β Apodis, γ Apodis, δ Octantis, δ1 Apodis, η Apodis and α Apodis. Consequently, ε Apodis itself is known as 異雀九 (Yì Què jiǔ, English: the Ninth 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.
- Gutierrez-Moreno, Adelina; Moreno, Hugo (June 1968), "A photometric investigation of the Scorpio-Centaurus association", Astrophysical Journal Supplement 15: 459, Bibcode:1968ApJS...15..459G, doi:10.1086/190168.
- Houk, Nancy (1979), Michigan catalogue of two-dimensional spectral types for the HD stars 1, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode:1978mcts.book.....H.
- Kazarovets, E. V. et al. (January 1999), "The 74th Special Name-list of Variable Stars", Information Bulletin on Variable Stars 4659: 1, Bibcode:1999IBVS.4659....1K.
- Evans, D. S. (June 20–24, 1966), "The Revision of the General Catalogue of Radial Velocities", in Batten, Alan Henry; Heard, John Frederick, Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30, University of Toronto: International Astronomical Union, Bibcode:1967IAUS...30...57E.
- Hohle, M. M.; Neuhäuser, R.; Schutz, B. F. (April 2010), "Masses and luminosities of O- and B-type stars and red supergiants", Astronomische Nachrichten 331 (4): 349, arXiv:1003.2335, Bibcode:2010AN....331..349H, doi:10.1002/asna.200911355.
- Pasinetti Fracassini, L. E.; Pastori, L.; Covino, S.; Pozzi, A. (February 2001). "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics". Astronomy and Astrophysics 367 (2): 521–524. arXiv:astro-ph/0012289. Bibcode:2001A&A...367..521P. doi:10.1051/0004-6361:20000451.
- Saffe, C. et al. (October 2008), "Spectroscopic metallicities of Vega-like stars", Astronomy and Astrophysics 490 (1): 297–305, arXiv:0805.3936, Bibcode:2008A&A...490..297S, doi:10.1051/0004-6361:200810260.
- Uesugi, Akira; Fukuda, Ichiro (1970), "Catalogue of rotational velocities of the stars", Contributions from the Institute of Astrophysics and Kwasan Observatory (University of Kyoto), Bibcode:1970crvs.book.....U.
- Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society 410 (1): 190–200, arXiv:1007.4883, Bibcode:2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x.
- "eps Aps -- Be Star", SIMBAD (Centre de Données astronomiques de Strasbourg), retrieved 2012-07-08.
- "The Colour of Stars", Australia Telescope, Outreach and Education (Commonwealth Scientific and Industrial Research Organisation), December 21, 2004, retrieved 2012-01-16.
- Samus, N. N.; Durlevich, O. V.; Kazarovets, R. V., "eps Aps", General Catalogue of Variable Stars (Sternberg Astronomical Institute), retrieved 2012-07-09.
- (Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 29 日