17 Aquarii
Star in the constellation Aquarius / From Wikipedia, the free encyclopedia
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 | −09° 19′ 09.5823″[1] |
Apparent magnitude (V) | 5.99[2] |
Characteristics | |
Spectral type | K4/5 III[3] |
B−V color index | 1.516±0.008[2] |
Astrometry | |
Radial velocity (Rv) | 18.2±2.9[4] km/s |
Proper motion (μ) | RA: −29.659[1] mas/yr Dec.: −29.022[1] mas/yr |
Parallax (π) | 4.9125 ± 0.1260 mas[1] |
Distance | 660 ± 20 ly (204 ± 5 pc) |
Absolute magnitude (MV) | −0.73[2] |
Orbit[5] | |
Period (P) | 7,290 d |
Eccentricity (e) | 0.4 |
Details | |
17 Aqr A | |
Luminosity | 495.46[2] L☉ |
Surface gravity (log g) | 1.74±0.14[6] cgs |
Temperature | 3,951±14[6] K |
Metallicity [Fe/H] | −0.10±0.06[6] dex |
Other designations | |
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]