Chi Octantis
Star in the constellation Octans
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Chi Octantis, Latinized from χ Octantis, is a solitary star[14] located in the southern circumpolar constellation Octans. It is faintly visible to the naked eye as an orange-hued star with an apparent magnitude of 5.28.[2] The object is located relatively close at a distance of 261 light years based on Gaia EDR3 parallax measurements,[1] but it is receding with a heliocentric radial velocity 33.6 km/s.[5] At its current distance, Chi Octantis' brightness is diminished by 0.24 magnitudes due to interstellar dust.[15] It has an absolute magnitude of +0.81.[6]
 | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Octans |
| Right ascension | 18h 54m 47.14062s[1] |
| Declination | −87° 36′ 21.0359″[1] |
| Apparent magnitude (V) | 5.28±0.01[2] |
| Characteristics | |
| Spectral type | K3 III[3] |
| U−B color index | +1.60[4] |
| B−V color index | +1.28[4] |
| Astrometry | |
| Radial velocity (Rv) | 33.6±3.1[5] km/s |
| Proper motion (μ) | RA: −36.555 mas/yr[1] Dec.: −135.715 mas/yr[1] |
| Parallax (π) | 12.5114±0.0730 mas[1] |
| Distance | 261 ± 2 ly (79.9 ± 0.5 pc) |
| Absolute magnitude (MV) | +0.81[6] |
| Details | |
| Mass | 1.25±0.33[7] M☉ |
| Radius | 15.6±0.8[8] R☉ |
| Luminosity | 73.6±0.7[9] L☉ |
| Surface gravity (log g) | 2.19[10] cgs |
| Temperature | 4,266+99 −97[7] K |
| Metallicity [Fe/H] | +0.10[10] dex |
| Rotational velocity (v sin i) | <1[11] km/s |
| Other designations | |
| χ Oct, 30 G. Octantis[12], CD−87°92, CPD−87°274, FK5 922, GC 25207, HD 164461, HIP 92824, HR 6721, SAO 258799[13] | |
| Database references | |
| SIMBAD | data |
Chi Octantis is an evolved red giant with a stellar classification of K3 III.[3] It has 125% the mass of the Sun and an enlarged radius of 14.45 R☉ due to its evolved state.[7] It radiates 73.6 times the luminosity of the Sun[9] from its photosphere at an effective temperature of 4,266 K.[7] Chi Octantis is metal enriched with an iron abundance 126% that of the Sun ([Fe/H] = +0.10)[10] and spins slowly with a projected rotational velocity less than 1 km/s−1.[11]