| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquila |
| Right ascension | 19h 41m 05.528s [2] |
| Declination | +13° 48′ 56.45″ [2] |
| Apparent magnitude (V) | 5.988 |
| Characteristics | |
| Spectral type | B5V |
| U−B color index | −0.52 |
| B−V color index | −0.08 |
| Variable type | Eclipsing binary [3] |
| Astrometry | |
| Radial velocity (Rv) | −14.2 ± 2 km/s |
| Proper motion (μ) | RA: −0.04 ± 0.60 [2] mas/yr Dec.: −11.47 ± 0.43 [2] mas/yr |
| Parallax (π) | 0.49±0.62 mas [2] |
| Orbit [3] | |
| Primary | QS Aquilae AB (eclipsing pair) |
| Companion | QS Aquilae C |
| Period (P) | 77.0±4.3 yr |
| Semi-major axis (a) | 0.111±0.045″ |
| Eccentricity (e) | 0.947±0.038 |
| Inclination (i) | 61.2±3.6° |
| Longitude of the node (Ω) | 144.5±5.1° |
| Periastron epoch (T) | 1962.3±2.3 |
| Argument of periastron (ω) (secondary) | 336.8±4.7° |
| Orbit [3] | |
| Primary | QS Aquilae A |
| Companion | QS Aquilae B |
| Period (P) | 2.5132987±0.0000075 d |
| Semi-major axis (a) | 13.78±0.11 R⊙ |
| Inclination (i) | 83.6±1.3° |
| Semi-amplitude (K1) (primary) | 73.98±0.33 km/s |
| Semi-amplitude (K2) (secondary) | 201.76±2.09 km/s |
| Other designations | |
| KUI 93, QS Aql, BD+13°4098, HD 185936, HIP 96840, HR 7486, WDS J19411+1349, 2MASS J19410553+1348565 [4] | |
| Database references | |
| SIMBAD | data |
QS Aquilae is a triple or quadruple star system consisting of an eclipsing binary in a 2.5 day orbit around which a third star orbits in 77 years. [3] There is some indication that there is a fourth component with a period of roughly 18 years. [5] Located in the constellation Aquila, its visual magnitude varies from 5.93 to 6.06, making it barely visible to the naked eye. [6]
The star's variability was discovered photometrically by Paul Guthnick and Richard Prager in 1930. It was given its variable star designation in 1934. [7]
