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.)
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- (Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 29 日