HD 204904

HD 204904
Location of HD 204904 on the map (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Octans
Right ascension 21h 38m 56.38010s[1]
Declination −79° 26′ 33.2989″[1]
Apparent magnitude (V) 6.17±0.01[2]
Characteristics
Spectral type F6 IV[3] or F4 IV[4]
U−B color index +0.02[5]
B−V color index +0.46[5]
Astrometry
Radial velocity (Rv)−5.2±0.5[6] km/s
Proper motion (μ) RA: +71.185 mas/yr[1]
Dec.: −26.928 mas/yr[1]
Parallax (π)15.369 ± 0.0195 mas[1]
Distance212.2 ± 0.3 ly
(65.07 ± 0.08 pc)
Absolute magnitude (MV)+2.13[7]
Details
Mass1.53[8] M☉
Radius2.87±0.15[9] R☉
Luminosity12.1±0.1[1] L☉
Surface gravity (log g)3.67+0.10
−0.09[10] cgs
Temperature6,443±80[11] K
Metallicity [Fe/H]−0.20±0.06[12] dex
Rotational velocity (v sin i)12±1.6[13] km/s
Age2.56[8] Gyr
Other designations
59 G. Octantis[14], CD−79°856, CPD−79°1158, FK5 3723, GC 30221, HD 204904, HIP 106881, HR 8234, SAO 257942, TIC 354944747[15]
Database references
SIMBADdata

HD 204904 (HR 8234; 59 G. Octantis) is a spectroscopic binary located in the southern circumpolar constellation Octans. It has an apparent magnitude of 6.17,[2] placing it near the limit for naked eye visibility, even under ideal conditions. The object is located relatively close at distance of 212 light-years based on Gaia DR3 parallax measurements[1] and it is drifting closer with a heliocentric radial velocity of −5.2 km/s.[6] At its current distance, HD 204904's brightness is diminished by 0.19 magnitudes due to interstellar extinction[16] and it has an absolute magnitude of +2.13.[7]

HD 204904 has a stellar classification of either F6 IV or F4 IV,[4] indicating that it is a slightly evolved F-type subgiant. It has 1.53 times the mass of the Sun[8] and a slightly enlarged radius 2.87 times that of the Sun's.[9] It radiates 12.1 times the luminosity of the Sun[1] from its photosphere at an effective temperature of 6,443 K,[11] giving it the typical yellowish-white hue of an F-type star. HD 204904 is metal deficient with an iron abundance of [Fe/H] = −0.20 or 63.1% of the Sun's iron abundance.[12] It is estimated to be 2.56 billion years old[8] and it spins modestly with a projected rotational velocity of 12 km/s.[13]

In 2014, J. R. De Medeiros and colleagues detected radial velocity variations from the star, indicating that it was a spectroscopic binary.[13] However, the system does not have a defined orbit.[17]

  1. ^ a b c d e f g 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. ^ Cite error: The named reference Houk1975 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Malaroda1975 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Johnson1966 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Gontcharov2006 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  8. ^ a b c d Cite error: The named reference David2015 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Kervella2004 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Stassun2019 was invoked but never defined (see the help page).
  11. ^ a b Cite error: The named reference Casagrande2011 was invoked but never defined (see the help page).
  12. ^ a b Cite error: The named reference Netopil2017 was invoked but never defined (see the help page).
  13. ^ a b c Cite error: The named reference De Medeiros2014 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 SIMBAD was invoked but never defined (see the help page).
  16. ^ Cite error: The named reference Gontcharov2017 was invoked but never defined (see the help page).
  17. ^ Cite error: The named reference Tokovinin2014 was invoked but never defined (see the help page).