97 Aquarii
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquarius |
| Right ascension | 23h 22m 39.17113s |
| Declination | −15° 02′ 21.6245″ |
| Apparent magnitude (V) | 5.20 (5.59/6.72) |
| Characteristics | |
| Spectral type | A2 V + A7 V |
| U−B color index | +0.10 |
| B−V color index | +0.20 |
| Astrometry | |
| Radial velocity (Rv) | −12 km/s |
| Proper motion (μ) | RA: +117.00 mas/yr Dec.: +16.48 mas/yr |
| Parallax (π) | 15.30±0.79 mas |
| Distance | 210 ± 10 ly (65 ± 3 pc) |
| Orbit | |
| Period (P) | 64.62 yr |
| Semi-major axis (a) | 0.408″ |
| Eccentricity (e) | 0.140 |
| Inclination (i) | 77.6° |
| Longitude of the node (Ω) | 276.3° |
| Periastron epoch (T) | 1941.29 |
| Argument of periastron (ω) (secondary) | 354.6° |
| Details | |
| Rotational velocity (v sin i) | 175 km/s |
| Other designations | |
| BD−15°6406, HD 220278, HIP 115404, HR 8890, SAO 165658. | |
| Database references | |
| SIMBAD | data |
97 Aquarii (abbreviated 97 Aqr) is a binary star system in the equatorial constellation of Aquarius. 97 Aquarii is the Flamsteed designation. The combined apparent visual magnitude of the system is 5.20; the brighter star is magnitude 5.59 while the companion is magnitude 6.72. Based upon an annual parallax shift of 15.30 milliarcseconds, this system is at a distance of around 210 light-years (64 parsecs) from Earth.
The two stars in this system orbit each other over a period of 64.62 years at an eccentricity of 0.14. Both are A-type main sequence stars; the primary has a stellar classification of A2 V while its companion is A7 V. Their composite spectrum shows the properties of a Lambda Boötis star, which means it displays peculiar abundances of certain elements.