Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Aquarius |
Right ascension | 21h 09m 35.64888s [1] |
Declination | –11° 22′ 18.0851″ [1] |
Apparent magnitude (V) | 4.52 [2] |
Characteristics | |
Spectral type | G8 III [3] |
U−B color index | +0.66 [2] |
B−V color index | +0.94 [2] |
Astrometry | |
Radial velocity (Rv) | −11.23 [4] km/s |
Proper motion (μ) |
RA: +94.12
[1]
mas/
yr Dec.: −14.62 [1] mas/ yr |
Parallax (π) | 20.47 ± 0.21 mas [1] |
Distance | 159 ± 2
ly (48.9 ± 0.5 pc) |
Absolute magnitude (MV) | +0.93 [5] |
Details | |
Mass | 2.35 [5] M☉ |
Radius | 8 [4] R☉ |
Luminosity | 37 [4] L☉ |
Surface gravity (log g) | 2.8 [4] cgs |
Temperature | 4,920 [4] K |
Metallicity [Fe/H] | −0.15 [4] dex |
Rotational velocity (v sin i) | 0.0 [4] km/s |
Age | 708 [5] Myr |
Other designations | |
Database references | |
SIMBAD | data |
Nu Aquarii (ν Aqr, ν Aquarii) is the Bayer designation for a star in the equatorial constellation of Aquarius.
With an apparent visual magnitude of 4.52, [2] Nu Aquarii is visible to the naked eye. Its distance from Earth, as determined from parallax measurements, is around 159 light-years (49 parsecs). At an estimated age of 708 million years, [5] it has evolved into a giant star with a spectrum that matches a stellar classification of G8 III. [3] It has than double the mass of the Sun [5] and has expanded to eight [4] times the Sun's radius. Nu Aquarii is radiating 37-fold [4] the luminosity of the Sun from its outer atmosphere at an effective temperature of 4,920 K. [4] At this heat, the star is glowing with the yellowish hue of a G-type star. [7]
Together with μ Aquarii, it is Albulaan /ˌælbjəˈlɑːn/, a name derived from the Arabic term al-bulaʽān (ألبولعان), meaning "the two swallowers". This star, along with ε Aqr (Albali) and μ Aqr (Albulaan), were al Bulaʽ (البلع)—the Swallower. [8] [9]
In Chinese, 天壘城 (Tiān Lěi Chéng), meaning Celestial Ramparts, refers to an asterism consisting of ν Aquarii, ξ Aquarii, 46 Capricorni, 47 Capricorni, λ Capricorni, 50 Capricorni, 18 Aquarii, 29 Capricorni, 9 Aquarii, 8 Aquarii, 14 Aquarii, 17 Aquarii and 19 Aquarii. [10] Consequently, the Chinese name for ν Aquarii itself is 天壘城十 (Tiān Lěi Chéng shí, English: the Tenth Star of Celestial Ramparts). [11]