19 Sextantis

19 Sextantis
Location of 19 Sex on the map (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Sextans
Right ascension 10h 12m 48.36462s[1]
Declination +04° 36′ 52.8378″[1]
Apparent magnitude (V) 5.78±0.01[2]
Characteristics
Evolutionary stage red giant branch[3]
Spectral type K1 III[4] or K0 III[5]
U−B color index +1.11[6]
B−V color index +1.18[6]
Astrometry
Radial velocity (Rv)31.80±0.21[7] km/s
Proper motion (μ) RA: −50.538 mas/yr[1]
Dec.: −6.118 mas/yr[1]
Parallax (π)6.3184 ± 0.0625 mas[1]
Distance516 ± 5 ly
(158 ± 2 pc)
Details
Mass0.88+0.08
−0.03[3] M☉
Radius23.13±1.17[8] R☉
Luminosity241+4
−5[1] L☉
Temperature4,576±123[9] K
Metallicity [Fe/H]−0.53[10] dex
Rotational velocity (v sin i)2.5±0.8[4] km/s
Age7.94+1.83
−0.70[3] Gyr
Other designations
19 Sex, 34 G. Sextantis[11], AG+04°1386, BD+05°2301, GC 14022, HD 88547, HIP 50027, HR 4004, SAO 118164, TIC 277696329[12]
Database references
SIMBADdata

19 Sextantis (HD 88547; HR 4004; 34 G. Sextantis), or simply 19 Sex, is a solitary star[13] located in the equatorial constellation Sextans. It is faintly visible to the naked eye as an orange-hued point of light with an apparent magnitude of 5.78.[2] Gaia DR3 parallax measurements imply a distance of 516 light-years[1] and it is currently receding with a heliocentric radial velocity of 31.8 km/s.[7] At its current distance, 19 Sex's brightness is diminished by an interstellar extinction of 0.17 magnitudes.[14]

19 Sex has a stellar classification of K1 III,[4] indicating that it is an evolved K-type giant star that has ceased hydrogen fusion at it core and it has left the main sequence. It has also been given a slightly hotter class of K0 III.[5] Stellar evolution models from Stock et al. (2018) model it to be a red giant branch star (100% chance)[3] that is currently fusing a hydrogen shell around an inert helium core. It has 88% the mass of the Sun but at the age of 7.94 billion years,[3] it has expanded to 23.13 times the radius of the Sun.[8] It radiates 241 times the luminosity of the Sun[1] from its photosphere at an effective temperature of 4,576 K.[9] 19 Sex is metal deficient with an iron abundance of [Fe/H] = −0.53 or 29.5% of the Sun's[10] and it spins modestly with a projected rotational velocity of 2.5 km/s.[4]

  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. ^ a b c d e Cite error: The named reference Stock2018 was invoked but never defined (see the help page).
  4. ^ a b c d Cite error: The named reference Henry2000 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Adams1935 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Johnson1966 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Famaey2005 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference Kervella2004 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Stassun2019 was invoked but never defined (see the help page).
  10. ^ a b Cite error: The named reference Hekker2007 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Gould1879 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference Gontcharov2017 was invoked but never defined (see the help page).