19 Aquarii is a star in the zodiac constellation of Aquarius. With an apparent magnitude of about 5.7,[2] 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.[1] The star is moving closer to the Earth with a heliocentric radial velocity of −21 km/s.[5]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquarius |
| Right ascension | 21h 25m 13.01629s[1] |
| Declination | −09° 44′ 54.7923″[1] |
| Apparent magnitude (V) | +5.713[2] |
| Characteristics | |
| Spectral type | A8V[3] |
| B−V color index | +0.20[4] |
| Astrometry | |
| Radial velocity (Rv) | −20.6±1.8[5] km/s |
| Proper motion (μ) | RA: +25.943[1] mas/yr Dec.: −167.548[1] mas/yr |
| Parallax (π) | 12.5593 ± 0.1676 mas[1] |
| Distance | 260 ± 3 ly (80 ± 1 pc) |
| Absolute magnitude (MV) | 0.90[6] |
| Details | |
| Mass | 1.86[7] M☉ |
| Radius | 2.76+0.18 −0.16[1] R☉ |
| Luminosity | 26.1+0.4 −0.4[1] L☉ |
| Surface gravity (log g) | 4.13[7] cgs |
| Temperature | 8,078±275[7] K |
| Rotational velocity (v sin i) | 102[8] km/s |
| Age | 788[7] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This object is an A-type main-sequence star with a stellar classification of A8V.[3] It is around 788[7] million years old with a fairly fast rotation rate, as its projected rotational velocity is about 155 km/s,[8] so it must be rotating at least that fast. It has 1.86[7] times the mass of the Sun and 2.76[1] times the Sun's radius. 19 Aquarii is radiating 26[1] times the luminosity of the Sun from its photosphere at an effective temperature of 8,078 K.[7] Eggen has this star flagged as a blue straggler and a member of the HR1614 supercluster.[10]