HD 191220

HD 191220
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Octans
Right ascension 20h 24m 54.91771s[1]
Declination −83° 18′ 38.2301″[1]
Apparent magnitude (V) 6.14±0.01[2]
Characteristics
Spectral type A2/3 mA8-F0[3]
U−B color index +0.13[4]
B−V color index +0.20[4]
Astrometry
Radial velocity (Rv)0.1±1.3[5] km/s
Proper motion (μ) RA: +23.223 mas/yr[1]
Dec.: +6.228 mas/yr[1]
Parallax (π)13.331 ± 0.0247 mas[1]
Distance244.7 ± 0.5 ly
(75.0 ± 0.1 pc)
Absolute magnitude (MV)+1.76[6]
Details
Mass2.06±0.40[7] M☉
Radius2.17±0.06[8] R☉
Luminosity15.57[9] L☉
Surface gravity (log g)4.12±0.06[10] cgs
Temperature7,706±126[11] K
Metallicity [Fe/H]−0.02[12] dex
Age979±166[1] Myr
Other designations
45 G. Octantis[13], CD−83°253, CPD−83°695, GC 28176, HD 191220, HIP 100697, HR 7698, SAO 258856[14]
Database references
SIMBADdata

HD 191220, also known as HR 7698, is a solitary white hued star located in the southern circumpolar constellation Octans. It has an apparent magnitude of 6.14,[2] placing it near the limit for naked eye visibility. The object is located relatively close at a distance of 245 light years based on Gaia DR3 parallax measurements[1] but is slowly receding with a heliocentric radial velocity of 0.1 km/s.[5] At its current distance, HD 191220's brightness is diminished by 0.22 magnitudes due to interstellar dust.[15]

This is a chemically peculiar Am star[16] with a stellar classification of A2/3mA8-F0,[3] an A-type star with the metallic lines of a star with a class of A8-F0. It has double the mass of the Sun and 2.2 times its girth.[7] It radiates 15.57 times the luminosity of the Sun[9] from its photosphere at an effective temperature of 7,706 K.[11] HD 191220 is estimated to be nearly a billion years old[12] and has a near solar metallicity — what astronomers dub a star's abundance of chemical elements heavier than helium.[12]

  1. ^ a b c d e f Cite error: The named reference GaiaDR3 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 Cite error: The named reference Stassun2018 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Stassun2019 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference McDonald2012 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference AP1999 was invoked but never defined (see the help page).
  11. ^ a b Cite error: The named reference Bai2019 was invoked but never defined (see the help page).
  12. ^ a b c Cite error: The named reference Gontcharov2012 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Gould1879 was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference Gontcharov2017 was invoked but never defined (see the help page).
  16. ^ Cite error: The named reference Renson2009 was invoked but never defined (see the help page).