| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquila |
| Right ascension | 19h 54m 08.27613s [1] |
| Declination | −08° 34′ 27.1674″ [1] |
| Apparent magnitude (V) | 5.79 [2] |
| Characteristics | |
| Spectral type | K5 III [3] |
| U−B color index | +2.00 [2] |
| B−V color index | +1.664±0.006 [4] |
| Astrometry | |
| Radial velocity (Rv) | −49.5±2.9 [5] km/s |
| Proper motion (μ) | RA: +6.737 [1] mas/yr Dec.: −18.578 [1] mas/yr |
| Parallax (π) | 5.6650±0.1739 mas [1] |
| Distance | 580 ± 20 ly (177 ± 5 pc) |
| Absolute magnitude (MV) | −0.66 [4] |
| Details | |
| Radius | 41.7+2.0 −2.6 [1] R☉ |
| Luminosity | 391±14 [1] L☉ |
| Temperature | 3,972+130 −91 [1] K |
| Other designations | |
| 56 Aql, BD−08°5150, FK5 2131, GC 2343, HD 188154, HIP 97928, HR 7584, SAO 143894 [6] | |
| Database references | |
| SIMBAD | data |
56 Aquilae is a single [7] star in the equatorial constellation of Aquila. 56 Aquilae is its Flamsteed designation. Its apparent visual magnitude is 5.79, [2] meaning it is barely visible to the naked eye as a dim, orange-hued point of light, under ideal viewing conditions. The star is located at a distance of around 580 light years away from the Sun, based on parallax. [1] It is moving closer to the Earth with a heliocentric radial velocity of −50 km/s, [5] and is predicted to come as near as 222 light-years in around 3.3 million years.
This is an aging giant star with a stellar classification of K5 III, [3] having exhausted the supply of hydrogen at its core and expanded to 42 [1] times the Sun's radius. It is radiating 391 [1] times the luminosity of the Sun from its photosphere at an effective temperature of 3,972 K. [1] 56 Aquilae is a double star, [8] but it does not appear to be a binary star system. [7] It is one of the double stars profiled in Admiral William Henry Smyth's 1864 work, Sidereal Chromatics.
