Epsilon Aquarii
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquarius |
| Right ascension | 20h 47m 40.54957s |
| Declination | −09° 29′ 44.7969″ |
| Apparent magnitude (V) | 3.77 |
| Characteristics | |
| Evolutionary stage | Main sequence or subgiant |
| Spectral type | A1 V + KV |
| U−B color index | +0.029 |
| B−V color index | −0.001 |
| Variable type | Constant |
| Astrometry | |
| Radial velocity (Rv) | −19.82±0.58 km/s |
| Proper motion (μ) | RA: +33.923 mas/yr Dec.: −34.926 mas/yr |
| Parallax (π) | 13.3619±0.3737 mas |
| Distance | 244 ± 7 ly (75 ± 2 pc) |
| Absolute magnitude (MV) | −0.46 |
| Orbit | |
| Primary | A |
| Companion | B |
| Period (P) | 1.2 years |
| Semi-major axis (a) | 25.9 mas 1.7 AU |
| Details | |
| A | |
| Mass | 2.98±0.03 M☉ |
| Radius | 4.2 R☉ |
| Luminosity | 161±9 L☉ |
| Surface gravity (log g) | 3.66±0.14 cgs |
| Temperature | 9,622±327 K |
| Metallicity [Fe/H] | −0.08±0.35 dex |
| Rotational velocity (v sin i) | 118.0±5.9 km/s |
| Age | 388 Myr |
| B | |
| Mass | 0.61 M☉ |
| Radius | 0.57 R☉ |
| Temperature | 4,070 K |
| Other designations | |
| Albali, ε Aqr, 2 Aquarii, BD−10°5506, FK5 781, HD 198001, HIP 102618, HR 7950, SAO 144810 | |
| Database references | |
| SIMBAD | data |
Epsilon Aquarii is a binary star system in the equatorial zodiac constellation of Aquarius, located near the western constellation border with Capricornus. Its identifier is a Bayer designation that is Latinized from ε Aquarii, and abbreviated Eps Aqr or ε Aqr, respectively. It has the proper name Albali /ælˈbeɪli/, now formally recognized by the IAU. This system is visible to the naked eye as a point of light with an apparent visual magnitude of 3.77, and has an absolute magnitude of −0.46. Based upon parallax measurements taken by the Gaia spacecraft, it is located at a distance of approximately 244 light-years (75 pc) from Earth. The star is drifting closer with a radial velocity of −20 km/s.