  | |
| 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] |
| Distance | 516 ± 5 ly (158 ± 2 pc) |
| Details | |
| Mass | 0.88+0.08 −0.03 [3] M☉ |
| Radius | 23.13±1.17 [8] R☉ |
| Luminosity | 241+4 −5 [1] L☉ |
| Temperature | 4,576±123 [9] K |
| Metallicity [Fe/H] | −0.53 [10] dex |
| Rotational velocity (v sin i) | 2.5±0.8 [4] km/s |
| Age | 7.94+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 | |
| SIMBAD | data |
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]
