Iota Apodis
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.
| 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: −1.844 ± 0.266 mas/yr Dec.: −10.811 ± 0.303 mas/yr |
| Parallax (π) | 3.1403 ± 0.1782 mas |
| Distance | 1,040 ± 60 ly (320 ± 20 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 |
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.