Iota Octantis

ι Octantis
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Octans
Right ascension 12h 54m 58.80949s[1]
Declination −85° 07′ 24.1041″[1]
Apparent magnitude (V) 5.83 + 6.75[2]
Characteristics
Spectral type K0 III[3]
U−B color index +0.79[4]
B−V color index +1.02[4]
Astrometry
Radial velocity (Rv)53.4±0.7[5] km/s
Proper motion (μ) RA: +67.20[1] mas/yr
Dec.: +24.76[1] mas/yr
Parallax (π)9.27 ± 0.46 mas[1]
Distance350 ± 20 ly
(108 ± 5 pc)
Absolute magnitude (MV)+0.29
Details[6]
Mass2.49+1.48
−1.31 M☉
Radius12.43[7] R☉
Luminosity81±9 L☉
Temperature4,890±110 K
Metallicity [Fe/H]−0.3 dex
Rotational velocity (v sin i)1.9±1.3[8] km/s
Age725[9] 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
SIMBADdata

Iota Octantis, Latinized, from ι Octantis is a double star[10] in the southern circumpolar constellation Octans. The "A" component has an apparent magnitude of 5.83,[2] making it faintly visible to the naked eye under ideal conditions, but the "B" component can't be seen due to its faintness.[2] The system is located at a distance of 350 light years[1] based on its annual parallax shift, but is drifting away at a rate of 53.4 km/s.[5]

Iota Octantis A has a classification of K0 III,[3] which indicates that it is an evolved K-type star that exhausted hydrogen at its core and left the main sequence. It has an angular diameter of 1.07 arcseconds,[11] which yields a radius 12.43 times that of the Sun at its estimated distance.[7] At present Iota Octantis A has 2.49 times the mass of the Sun[6] and radiates at 81 times the luminosity of the Sun[6] from its enlarged photosphere at an effective temperature of 4,890 K,[6] which gives it an orangish-yellow hue. Iota Octantis is metal deficient[6] and spins slowly with a projected rotational velocity of 1.9 km/s.[8]

Eggleton et al. states that both stars have similar spectral types,[10] but there is a faint tenth magnitude companion with a classification of F8 located 60.1″ away,[12] which is unrelated to the two.

  1. ^ a b c d e f Cite error: The named reference VanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b c Cite error: The named reference Fabricius2007 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Houk1975 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Johnson1966 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Kharchenko2007 was invoked but never defined (see the help page).
  6. ^ a b c d e Cite error: The named reference Charbonnel2020 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Lang2006 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference DeMederios2014 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference DDR2022 was invoked but never defined (see the help page).
  10. ^ a b Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Stevens2017 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Manson2001 was invoked but never defined (see the help page).