17 Aquarii
Star in the constellation Aquarius
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17 Aquarii, abbreviated 17 Aqr, is a spectroscopic binary[5] 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.[2] The distance to 17 Aqr can be estimated from its annual parallax shift of 4.9 mas,[1] which yields a separation of around 660 light years. It is moving further away with a heliocentric radial velocity of 18 km/s.[4]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquarius |
| Right ascension | 21h 22m 56.25866s[1] |
| Declination | â09° 19â² 09.5823â³[1] |
| Apparent magnitude (V) | 5.99[2] |
| Characteristics | |
| Spectral type | K4/5 III[3] |
| BâV color index | 1.516±0.008[2] |
| Astrometry | |
| Radial velocity (Rv) | 18.2±2.9[4] km/s |
| Proper motion (μ) | RA: â29.659[1] mas/yr Dec.: â29.022[1] mas/yr |
| Parallax (Ï) | 4.9125±0.1260 mas[1] |
| Distance | 660 ± 20 ly (204 ± 5 pc) |
| Absolute magnitude (MV) | â0.73[2] |
| Orbit[5] | |
| Period (P) | 7,290 d |
| Eccentricity (e) | 0.4 |
| Details | |
| 17 Aqr A | |
| Luminosity | 495.46[2] Lâ |
| Surface gravity (log g) | 1.74±0.14[6] cgs |
| Temperature | 3,951±14[6] K |
| Metallicity [Fe/H] | â0.10±0.06[6] dex |
| Other designations | |
| 17 Aqr, BDâ09°5728, FK5 3705, HD 203525, HIP 105574, HR 8175, SAO 145351[7] | |
| Database references | |
| SIMBAD | data |
A preliminary orbit for the pair gives a period of 20 years and an eccentricity of 0.4.[5] The primary component is an aging giant star with a stellar classification of K4/5 III.[3] It is radiating 495[2] times the Sun's luminosity from its photosphere at an effective temperature of 3,951 K.[6]