HD 222806
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| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Octans |
| Right ascension | 23h 44m 40.8646s[1] |
| Declination | −78° 47′ 29.1861″[1] |
| Apparent magnitude (V) | 5.74±0.01[2] |
| Characteristics | |
| Spectral type | K1 III[3] |
| U−B color index | +1.06[4] |
| B−V color index | +1.11[4] |
| Astrometry | |
| Radial velocity (Rv) | 21.3±0.8[5] km/s |
| Proper motion (μ) | RA: +49.327 mas/yr[1] Dec.: +7.345 mas/yr[1] |
| Parallax (π) | 5.7766±0.0592 mas[1] |
| Distance | 565 ± 6 ly (173 ± 2 pc) |
| Absolute magnitude (MV) | −0.11[6] |
| Details | |
| Mass | 1.26[7] M☉ |
| Radius | 18.77[8] R☉ |
| Luminosity | 151±2[9] L☉ |
| Surface gravity (log g) | 1.95[7] cgs |
| Temperature | 4,865±122[10] K |
| Metallicity [Fe/H] | +0.37[11] dex |
| Rotational velocity (v sin i) | <1[12] km/s |
| Other designations | |
| 85 G. Octantis, CPD−79°1239, FK5 3906, GC 32960, HD 222806, HIP 117125, HR 8995, SAO 258179[13][14] | |
| Database references | |
| SIMBAD | data |
HD 222806 (HR 8995) is a suspected astrometric binary[15] in the southern circumpolar constellation Octans. It has an apparent magnitude of 5.74,[2] allowing it to be faintly seen with the naked eye. Parallax measurements place the system at a distance of 565 light years[1] and it is currently receding with a heliocentric radial velocity of 21 km/s.[5]
The visible component has a stellar classification of K1 III,[3] indicating that it is a red giant. At present it has 126% the mass of the Sun,[7] but has expanded to almost 19 times its girth.[8] It radiates at 151 times the luminosity of the Sun[9] from its enlarged photosphere at an effective temperature of 4,865 K,[10] giving it an orange hue. HD 222806 is metal enriched with an iron abundance over twice that of the Sun and is believed to be a member of the young disk population.[11] It spins with a projected rotational velocity lower than 1 km/s.[12]
