Gamma2 Octantis

γ² Octantis, Latinized to Gamma² Octantis (Gamma² Oct), is a solitary^[12] 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.^[6]

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′ 11.310″[1]
Apparent magnitude (V)	5.72±0.01[2]
Characteristics
Evolutionary stage	red clump[3]
Spectral type	K0 III[4]
U−B color index	+0.92[5]
B−V color index	+1.05[5]
Astrometry
Radial velocity (Rv)	27.2±2.9[6] 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]
Distance	320 ± 1 ly (98.3 ± 0.3 pc)
Absolute magnitude (MV)	+0.87[7]
Details[8]
Mass	1.15±0.15 M☉
Radius	10.54±0.28 R☉
Luminosity	52.6±1.3 L☉
Surface gravity (log g)	2.53±0.13 cgs
Temperature	4,788±58 K
Metallicity [Fe/H]	−0.04±0.04 dex
Rotational velocity (v sin i)	2.8±1.1[9] km/s
Other designations
γ2 Oct, 87 G. Octantis, CPD−82°907, HD 224362, HIP 118114, HR 9061, SAO 258996[10][11]
Database references
SIMBAD	data

Gamma² Oct has a stellar classification of K0 III,^[4] 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.^[8] It shines at 52.6 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,788 K,^[8] giving it a yellow-orange glow. Gamma² Oct has a metallicity around 91% that of the Sun^[8] and spins with a projected rotational velocity of about 3 km/s.^[9]