17 Aquarii
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquarius |
| Right ascension | 21h 22m 56.25866s |
| Declination | −09° 19′ 09.5823″ |
| Apparent magnitude (V) | 5.99 |
| Characteristics | |
| Spectral type | K4/5 III |
| B−V color index | 1.516±0.008 |
| Astrometry | |
| Radial velocity (Rv) | 18.2±2.9 km/s |
| Proper motion (μ) | RA: −29.659 mas/yr Dec.: −29.022 mas/yr |
| Parallax (π) | 4.9125±0.1260 mas |
| Distance | 660 ± 20 ly (204 ± 5 pc) |
| Absolute magnitude (MV) | −0.73 |
| Orbit | |
| Period (P) | 7,290 d |
| Eccentricity (e) | 0.4 |
| Details | |
| 17 Aqr A | |
| Luminosity | 495.46 L☉ |
| Surface gravity (log g) | 1.74±0.14 cgs |
| Temperature | 3,951±14 K |
| Metallicity [Fe/H] | −0.10±0.06 dex |
| Other designations | |
| 17 Aqr, BD−09°5728, FK5 3705, HD 203525, HIP 105574, HR 8175, SAO 145351 | |
| Database references | |
| SIMBAD | data |
17 Aquarii, abbreviated 17 Aqr, is a spectroscopic binary star system in the constellation of Aquarius. 17 Aquarii is the Flamsteed designation. It appears to the naked eye as a faint sixth magnitude star, having a combined apparent visual magnitude of 5.99. The distance to 17 Aqr can be estimated from its annual parallax shift of 4.9 mas, which yields a separation of around 660 light years. It is moving further away with a heliocentric radial velocity of 18 km/s.
A preliminary orbit for the pair gives a period of 20 years and an eccentricity of 0.4. The primary component is an aging giant star with a stellar classification of K4/5 III. It is radiating 495 times the Sun's luminosity from its photosphere at an effective temperature of 3,951 K.