| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquarius |
| Right ascension | 22h 21m 35.56816s[1] |
| Declination | −21° 35′ 53.6431″[1] |
| Apparent magnitude (V) | 5.135[2] |
| Characteristics | |
| Spectral type | K0 III[3] |
| B−Vcolor index | 1.054[2] |
| Astrometry | |
| Radial velocity (Rv) | +48.2[2] km/s |
| Proper motion (μ) | RA: −10.986[1]mas/yr Dec.: −83.914[1]mas/yr |
| Parallax (π) | 18.0015±0.1709 mas[1] |
| Distance | 181 ± 2 ly (55.6 ± 0.5 pc) |
| Absolute magnitude (MV) | +1.52[4] |
| Details[5] | |
| Mass | 1.35 M☉ |
| Radius | 7.86 R☉ |
| Luminosity | 30 L☉ |
| Surface gravity (log g) | 2.69 cgs |
| Temperature | 4,750 K |
| Metallicity[Fe/H] | −0.18±0.08 dex |
| Rotational velocity (v sin i) | 1.43 km/s |
| Age | 2.4[2] Gyr |
| Other designations | |
| 47 Aqr,BD−22°5897,FK5 1584,HD 212010,HIP 110391,HR 8516,SAO 191083[6] | |
| Database references | |
| SIMBAD | data |
47 Aquarii, abbreviated47 Aqr, is astar in thezodiacconstellation ofAquarius.47 Aquarii is itsFlamsteed designation. It is a faint star but visible to the naked eye in good seeing conditions, having anapparent visual magnitude of 5.135.[2] Based upon an annualparallax shift of18.0 mas,[1] it is located 181 light years away. At that distance, the visual magnitude of the star is diminished by anextinction of 0.088 due tointerstellar dust.[5] It is moving further from the Earth with a heliocentricradial velocity of +48 km/s.[2]
This is anevolvedgiant star currently on thered giant branch[5] with astellar classification of K0 III.[3] The star has 1.35 times themass of the Sun and has expanded to 7.86 times theSun's radius. It is radiating 30 times theSun's luminosity from its enlargedphotosphere at aneffective temperature of 4,750 K.[5]
