19 Aquilae
Star in the constellation Aquila
From Wikipedia, the free encyclopedia
19 Aquilae is a single[13] star located 142 light-years (44 parsecs) away from the Sun in the equatorial constellation of Aquila. 19 Aquilae is the Flamsteed designation. It is visible to the naked eye as a dim, yellow-white hued star with an apparent visual magnitude of 5.23.[2] The star is moving closer to the Earth with a heliocentric radial velocity of −46.7 km/s.[7]
Image captured from Mount Laguna, California | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Aquila |
| Right ascension | 19h 08m 59.91479s[1] |
| Declination | +06° 04′ 23.5840″[1] |
| Apparent magnitude (V) | 5.227[2] |
| Characteristics | |
| Evolutionary stage | main sequence[1] |
| Spectral type | F0 III-IV[3] |
| Apparent magnitude (U) | 5.59±0.010[4] |
| Apparent magnitude (B) | 5.57±0.007[5] |
| Apparent magnitude (V) | 5.23±0.009[5] |
| U−B color index | +0.020[2] |
| B−V color index | +0.345[2] |
| Variable type | suspected γ Dor[6] |
| Astrometry | |
| Radial velocity (Rv) | −46.7[7] km/s |
| Proper motion (μ) | RA: −13.024[1] mas/yr Dec.: −80.085[1] mas/yr |
| Parallax (π) | 21.0662±0.3703 mas[1] |
| Distance | 155 ± 3 ly (47.5 ± 0.8 pc) |
| Absolute magnitude (MV) | 1.94[8] |
| Details | |
| Mass | 1.50[9] M☉ |
| Radius | 2.46[9] R☉ |
| Luminosity | 12.4[9] L☉ |
| Surface gravity (log g) | 3.83[9] cgs |
| Temperature | 6,906[9] K |
| Metallicity [Fe/H] | +0.03[3] dex |
| Rotational velocity (v sin i) | 57.0[10] km/s |
| Age | 2.25[11] Gyr |
| Other designations | |
| 19 Sge, BD+05°4040, FK5 3530, HD 178596, HIP 94068, HR 7266, SAO 124318[12] | |
| Database references | |
| SIMBAD | data |
This object has a stellar classification of F0 III-IV,[3] with the luminosity class matching an evolving star transitioning from the subgiant to a giant stage. Poretti et al. (2003) list it as a suspected Gamma Doradus variable, and it is located near the cooler end of the instability strip on the Hertzsprung–Russell diagram.[6] These spatial coordinates are a source of X-ray emission, which is most likely coming from the star.[14]
19 Aquilae is an estimated 2.25[11] billion years old with a moderately high rate of spin, showing a projected rotational velocity of 57.0 km/s.[10] It has 1.5 times the mass of the Sun and 2.5 times the Sun's radius. The star is radiating 12.4 times the luminosity of the Sun from its photosphere at an effective temperature of 6,906 K.[9]