Iota Octantis
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Octans |
| A | |
| Right ascension | 12h 54m 58.80097s |
| Declination | −85° 07′ 24.1092″ |
| Apparent magnitude (V) | 5.83 |
| B | |
| Right ascension | 12h 54m 58.33659s |
| Declination | −85° 07′ 24.4647″ |
| Apparent magnitude (V) | 6.75 |
| Characteristics | |
| Spectral type | K0III + K0 |
| U−B color index | +0.79 |
| B−V color index | +1.02 |
| Astrometry | |
| Radial velocity (Rv) | 53.4±0.7 km/s |
| Proper motion (μ) | RA: +67.20 mas/yr Dec.: +24.76 mas/yr |
| Parallax (π) | 9.27±0.46 mas |
| Distance | 350 ± 20 ly (108 ± 5 pc) |
| Absolute magnitude (MV) | +0.29 |
| Details | |
| Mass | 2.49+1.48 −1.31 M☉ |
| Luminosity | 81±9 L☉ |
| Temperature | 4,890±110 K |
| Metallicity [Fe/H] | −0.3 dex |
| Rotational velocity (v sin i) | 1.9±1.3 km/s |
| Age | 725 Myr |
| Other designations | |
| ι Octantis, 16 G. Octantis, CPD−84°407, GC 17460, HD 111482, HIP 63031, HR 4870, SAO 258654, WDS J12550-8507AB | |
| Database references | |
| SIMBAD | data |
Iota Octantis, Latinized from ι Octantis, is a double star in the southern circumpolar constellation Octans. The two components are separated by less than an arc-second, so cannot be resolved without a telescope, but their combined apparent magnitude of 5.45 makes Iota Octantis faintly visible to the naked eye in dark skies. The system is located at a distance of 350 light years based on its annual parallax shift, and is drifting away at a rate of 53.4 km/s.
Iota Octantis A has a classification of K0 III, which indicates that it is an evolved K-type star that exhausted hydrogen at its core and left the main sequence. Iota Octantis B also has a spectral type of K0. At present Iota Octantis A has 2.49 times the mass of the Sun and radiates at 81 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,890 K, which gives it an orangish-yellow hue. Iota Octantis is metal deficient and spins slowly with a projected rotational velocity of 1.9 km/s.
Eggleton et al. states that both stars have similar spectral types, but there is a faint tenth magnitude companion with a classification of F8 located 60.1″ away, which is unrelated to the two.