19 Aquarii
White-hued hydrogen-burning star in the constellation Aquarius
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19 Aquarii is a star in the zodiac constellation of Aquarius. With an apparent magnitude of about 5.7,[3] the star is barely visible to the naked eye as a white-hued star (see Bortle scale). Parallax estimates put it at a distance of about 260 light years away from the Sun.[2] The star is moving closer to the Earth with a heliocentric radial velocity of −21 km/s.[7]
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Aquarius[1] |
| Right ascension | 21h 25m 13.01629s[2] |
| Declination | −09° 44′ 54.7923″[2] |
| Apparent magnitude (V) | +5.713[3] |
| Characteristics | |
| Evolutionary stage | main sequence[4] |
| Spectral type | A8V[5] |
| B−V color index | +0.20[6] |
| Astrometry | |
| Radial velocity (Rv) | −20.6±1.8[7] km/s |
| Proper motion (μ) | RA: +25.943[2] mas/yr Dec.: −167.548[2] mas/yr |
| Parallax (π) | 12.5593±0.1676 mas[2] |
| Distance | 260 ± 3 ly (80 ± 1 pc) |
| Absolute magnitude (MV) | 0.90[1] |
| Details | |
| Mass | 1.86[8] M☉ |
| Radius | 2.76+0.18 −0.16[2] R☉ |
| Luminosity | 26.1+0.4 −0.4[2] L☉ |
| Surface gravity (log g) | 4.13[8] cgs |
| Temperature | 8,078±275[8] K |
| Rotational velocity (v sin i) | 102[9] km/s |
| Age | 788[8] Myr |
| Other designations | |
| 19 Aqr, BD−10°5668, HD 203875, HIP 105761, HR 8195, SAO 145382[10] | |
| Database references | |
| SIMBAD | data |
This object is an A-type main-sequence star with a stellar classification of A8V.[5] It is around 788[8] million years old with a fairly fast rotation rate, as its projected rotational velocity is about 155 km/s,[9] so it must be rotating at least that fast. It has 1.86[8] times the mass of the Sun and 2.76[2] times the Sun's radius. 19 Aquarii is radiating 26[2] times the luminosity of the Sun from its photosphere at an effective temperature of 8,078 K.[8] Eggen has this star flagged as a blue straggler and a member of the HR 1614 supercluster.[11]