HD 222806

HD 222806
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]
Distance565 ± 6 ly
(173 ± 2 pc)
Absolute magnitude (MV)−0.11[6]
Details
Mass1.26[7] M☉
Radius18.77[8] R☉
Luminosity151±2[9] L☉
Surface gravity (log g)1.95[7] cgs
Temperature4,865±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
SIMBADdata

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]

  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 Cite error: The named reference Anders2019 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference Kervella2021 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference DR2 was invoked but never defined (see the help page).
  10. ^ a b Cite error: The named reference Stassun2019 was invoked but never defined (see the help page).
  11. ^ a b Cite error: The named reference Eggen1994 was invoked but never defined (see the help page).
  12. ^ a b Cite error: The named reference DeMederios2014 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 Gould1879 was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).