Gamma2 Octantis

For other stars with this Bayer designation, see γ Octantis.
γ2 Octantis
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Octans
Right ascension 23h 57m 32.8617s[1]
Declination −82° 10′ 11.30968″[1]
Apparent magnitude (V) 5.72±0.01[2]
Characteristics
Spectral type K0 III[3]
U−B color index +0.92[4]
B−V color index +1.05[4]
Astrometry
Radial velocity (Rv)27.2±2.9[5] km/s
Proper motion (μ) RA: −22.246 mas/yr[1]
Dec.: −23.235 mas/yr[1]
Parallax (π)10.1771 ± 0.0345 mas[1]
Distance320 ± 1 ly
(98.3 ± 0.3 pc)
Absolute magnitude (MV)+0.87[6]
Details[7]
Mass1.15±0.15 M☉
Radius10.54±0.28 R☉
Luminosity52.6±1.3 L☉
Surface gravity (log g)2.53±0.13 cgs
Temperature4,788±58 K
Metallicity [Fe/H]−0.04±0.04 dex
Rotational velocity (v sin i)2.8±1.1[8] km/s
Other designations
γ2 Oct, 87 G. Octantis, CPD−82°907, HD 224362, HIP 118114, HR 9061, SAO 258996[9][10]
Database references
SIMBADdata

γ2 Octantis, Latinized to Gamma2 Octantis (Gamma2 Oct), is a solitary[11] star in the southern circumpolar constellation Octans. It has an apparent magnitude of 5.72,[2] allowing it to be faintly seen with the naked eye. Parallax measurements place the object at a distance of 320 light years[1] and is currently receding with a heliocentric radial velocity of 27 km/s.[5]

Gamma2 Oct has a stellar classification of K0 III,[3] indicating that it is a red giant. At present it has 115% the mass of the Sun but has expanded to 10.54 times its girth.[7] It shines at 52.6 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,788 K,[7] giving it a yellow-orange glow. Gamma2 Oct has a poorly constrained metallicity 91% that of the Sun[7] and spins with a projected rotational velocity of about 3 km/s.[8]

  1. ^ a b c d e Cite error: The named reference EDR3 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 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 Gontcharov2006 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  7. ^ a b c d Cite error: The named reference Ottoni2022 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 SIMBAD was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Gould1879 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).