101 Aquarii
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquarius |
| Right ascension | 23h 33m 16.62300s |
| Declination | −20° 54′ 52.2155″ |
| Apparent magnitude (V) | 4.71 |
| Characteristics | |
| Spectral type | A0 V |
| U−B color index | +0.00 |
| B−V color index | +0.02 |
| Astrometry | |
| Radial velocity (Rv) | +15 km/s |
| Proper motion (μ) | RA: −3.41 mas/yr Dec.: +8.46 mas/yr |
| Parallax (π) | 11.11±0.67 mas |
| Distance | 290 ± 20 ly (90 ± 5 pc) |
| Details | |
| Rotational velocity (v sin i) | 180 km/s |
| Other designations | |
| BD−21 6437, HD 221565, HIP 116247, HR 8939, SAO 191988 | |
| Database references | |
| SIMBAD | data |
101 Aquarii (abbreviated 101 Aqr) is a star in the equatorial constellation of Aquarius. 101 Aquarii is the Flamsteed designation, although it also bears the Bayer designation b3 Aquarii. 101 Aqr is a double star with the designation B 1900. The combined apparent visual magnitude of the pair is 4.71, which is bright enough to be seen with the naked eye from the suburbs. The distance of this star from Earth is estimated as 290 light-years (89 parsecs) based upon parallax measurements.
The brighter member of this system has an apparent magnitude of 4.81. It is an A-type main sequence star with a stellar classification of A0 V. This star is spinning rapidly with a projected rotational velocity of 1 km/s. The fainter companion is a magnitude 7.43 star at an angular separation of 0.840 arcseconds.