Omega Octantis

ω Octantis
Location of ω Oct (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Octans
Right ascension 15h 11m 08.79214s[1]
Declination −84° 47′ 16.0295″[1]
Apparent magnitude (V) 5.87±0.01[2]
Characteristics
Evolutionary stage main sequence[3]
Spectral type B9.5 V[4]
U−B color index −0.13[5]
B−V color index −0.06[5]
Astrometry
Radial velocity (Rv)−7.6±3[6] km/s
Proper motion (μ) RA: +2.984 mas/yr[1]
Dec.: −9.385 mas/yr[1]
Parallax (π)9.9406 ± 0.0591 mas[1]
Distance328 ± 2 ly
(100.6 ± 0.6 pc)
Absolute magnitude (MV)+0.94[7]
Details
Mass2.54[3] M☉
Radius2.35±0.06[8] R☉
Luminosity50.5+2.5
−2.4[3] L☉
Surface gravity (log g)4.21[9] cgs
Temperature10,759±366[9] K
Metallicity [Fe/H]0.00[10] dex
Rotational velocity (v sin i)36[11] km/s
Age197[9] Myr
Other designations
ω Oct, 23 G. Octantis[12], CPD−84°490, GC 20223, HD 131596, HIP 74296, HR 5557, SAO 258717[13]
Database references
SIMBADdata

Omega Octantis, (latinized from ω Octantis), is a solitary,[14] bluish-white hued star located in the southern circumpolar constellation Octans. It has an apparent magnitude of 5.87,[2] allowing it to be faintly seen with the naked eye. Based on the object's parallax measurements, it is estimated to be 328 light years distant.[1] However, it is drifting closer with a heliocentric radial velocity −7.6 km/s.[6]

Omega Octantis has a stellar classification of B9.5 V,[4] indicating that it is a main-sequence star between the B9 and A0 classes. Helmut A. Abt & Nidia I. Morrell gave a slightly updated class of B9.5 Vs,[15] which includes sharp (narrow) absorption lines in Omega Octantis' spectrum due to slow rotation. It has a mass 2.54 times that of the Sun[3] and is calculated to be 197 million years old,[9] having completed 40% of its main sequence lifetime.[3] It has a luminosity of 50.5 L☉,[3] which comes from a radius of 2.35 R☉ and an effective temperature of 10,759 K. In 2012, George A. Gontcharov calculated a solar metallicity for Omega Octantis,[10] and it is spinning modestly with a projected rotational velocity of 36 km/s.[11] The slow rotation is consistent with the spectral classification from Abt & Morell (1995).[15]

  1. ^ a b c d e Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference Tycho2000 was invoked but never defined (see the help page).
  3. ^ a b c d e f Cite error: The named reference Zorec2012 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Houk1975 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Johnson1966 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Gontcharov2006 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Stassun2019 was invoked but never defined (see the help page).
  9. ^ a b c d Cite error: The named reference David2015 was invoked but never defined (see the help page).
  10. ^ a b Cite error: The named reference Gontcharov2012 was invoked but never defined (see the help page).
  11. ^ a b Cite error: The named reference Levato2004 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Gould1879 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  15. ^ a b Cite error: The named reference Abt1995 was invoked but never defined (see the help page).