Iota Apodis
 Location of ι Apodis (circled) |
|
| Observation data Epoch J2000 Equinox J2000 |
|
|---|---|
| Constellation | Apus |
| Right ascension | 17h 22m 05.87559s |
| Declination | –70° 07′ 23.5400″ |
| Apparent magnitude (V) | 5.41 (5.90/6.46) |
| Characteristics | |
| Spectral type | B9 V + B9.5 V |
| U−B color index | −0.23 |
| B−V color index | −0.04 |
| Astrometry | |
| Radial velocity (Rv) | −4.3 km/s |
| Proper motion (μ) |
RA: −1.94 mas/yr Dec.: −10.99 mas/yr |
| Parallax (π) | 2.47 ± 0.50mas |
| Distance | approx. 1,300 ly (approx. 400 pc) |
| Orbit | |
| Period (P) | 59.32±3.0 yr |
| Semi-major axis (a) | 0.115±0.005″ |
| Eccentricity (e) | 0.172±0.050 |
| Inclination (i) | 69.4±3.0° |
| Longitude of the node (Ω) | 119.6±4.0° |
|
Argument of periastron (ω) (secondary) |
270.5±7.0° |
| Details | |
| ι Aps A | |
| Mass | 3.89±1.02 M☉ |
| ι Aps B | |
| Mass | 3.45±0.90 M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
Iota Apodis (ι Aps, ι Apodis) is the Bayer designation for a binary star system in the southern circumpolar constellation of Apus. It is a faint target at an apparent visual magnitude of 5.41, but still visible to the naked eye from suitably dark skies. The distance to this star can be roughly gauged from parallax measurements, yielding an estimate of 1,300 light-years (400 parsecs) with a 20% margin of error.
Both stars are B-type main sequence stars, which indicates they shine with a blue-white hue. The brighter component has a stellar classification of B9 V and an apparent magnitude 5.90, while the second member is a B9.5 V star with a magnitude of 6.46. The pair have an angular separation of 0.091 arcseconds with an estimated orbital period of 59.32 years. They are about 3.89 and 3.45 times as massive as the Sun.
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 ι Apodis, ζ Apodis, β Apodis, γ Apodis, δ Octantis, δ1 Apodis, η Apodis, α Apodis and ε Apodis. Consequently, ι Apodis itself is known as 異雀二 (Yì Què èr, English: the Second Star of Exotic Bird.)
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