QS Aquilae
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquila |
| Right ascension | 19h 41m 05.528s |
| Declination | +13° 48′ 56.45″ |
| 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 |
| Astrometry | |
| Radial velocity (Rv) | −14.2 ± 2 km/s |
| Proper motion (μ) | RA: −0.04 ± 0.60 mas/yr Dec.: −11.47 ± 0.43 mas/yr |
| Parallax (π) | 0.49±0.62 mas |
| Orbit | |
| 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 | |
| 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 | |
| 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. There is some indication that there is a fourth component with a period of roughly 18 years. Located in the constellation Aquila, its visual magnitude varies from 5.93 to 6.06, making it barely visible to the naked eye.
The star's variability was discovered photometrically by Paul Guthnick and Richard Prager in 1930. It was given its variable star designation in 1934.