Epsilon Aquarii
Star in the constellation Aquarius / From Wikipedia, the free encyclopedia
Epsilon Aquarii, Latinized from ε Aquarii, is a single[10] star in the equatorial zodiac constellation of Aquarius, located near the western constellation border with Capricornus. It has the proper name Albali /ælˈbeɪli/, now formally recognized by the IAU.[11][12] This is a white-hued star that is visible to the naked eye with an apparent visual magnitude of 3.77,[2] with an absolute magnitude of −0.46.[6] Based upon parallax measurements taken by the Gaia spacecraft, it is located at a distance of approximately 244 light-years (75 pc) from Earth.[1] The star is drifting closer with a radial velocity of −20 km/s.[1]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Aquarius |
Right ascension | 20h 47m 40.54957s[1] |
Declination | −09° 29′ 44.79693″[1] |
Apparent magnitude (V) | 3.77[2] |
Characteristics | |
Evolutionary stage | Main sequence[3] |
Spectral type | A1 V[2] |
U−B color index | +0.029[4] |
B−V color index | –0.001[4] |
Variable type | Constant[5] |
Astrometry | |
Radial velocity (Rv) | −19.82±0.58[1] km/s |
Proper motion (μ) | RA: +33.923 mas/yr[1] Dec.: -34.926 mas/yr[1] |
Parallax (π) | 13.3619 ± 0.3737 mas[1] |
Distance | 244 ± 7 ly (75 ± 2 pc) |
Absolute magnitude (MV) | −0.46[6] |
Details | |
Mass | 2.98±0.03[3] M☉ |
Radius | 2.5[7] R☉ |
Luminosity | 138.0+5.4 −5.2[3] L☉ |
Surface gravity (log g) | 3.66±0.14[8] cgs |
Temperature | 9,622±327[8] K |
Metallicity [Fe/H] | −0.08±0.35[5] dex |
Rotational velocity (v sin i) | 118.0±5.9[6] km/s |
Age | 388[8] Myr |
Other designations | |
Database references | |
SIMBAD | data |
This is an A-type main-sequence star with a stellar classification of A1 V.[2] It is estimated to be estimated 388[8] million years old with a high rate of spin, showing a projected rotational velocity of around 118 km/s.[6] The elemental abundances in the stellar atmosphere are close to solar, with pronounced underabundances of aluminium and strontium.[5] The star has three[3] times the mass of the Sun and about 2.5[7] times the Sun's radius. It is radiating 138[3] times the luminosity of the Sun from its photosphere at an effective temperature of 9,622 K.[8]