Nu Aquarii
Star in the constellation Aquarius
From Wikipedia, the free encyclopedia
Nu Aquarii is a star in the equatorial constellation of Aquarius. The name is a Bayer designation that is Latinized from ν Aquarii, and abbreviated Nu Aqr or ν Aqr. With an apparent visual magnitude of 4.52,[4] Nu Aquarii is faintly visible to the naked eye. Its distance from Earth, as determined from parallax measurements, is 162 light-years (50 parsecs). The star is drifting closer to the Sun with a radial velocity of â11 km/s.[5]
 | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquarius |
| Right ascension | 21h 09m 35.648s[1] |
| Declination | â11° 22â² 18.09â³[1] |
| Apparent magnitude (V) | 4.520[2] |
| Characteristics | |
| Evolutionary stage | red giant branch[1] |
| Spectral type | G8 III[3] |
| UâB color index | +0.66[4] |
| BâV color index | +0.943[5] |
| Astrometry | |
| Radial velocity (Rv) | â11.23[5] km/s |
| Proper motion (μ) | RA: +93.613 mas/yr[1] Dec.: â15.494 mas/yr[1] |
| Parallax (Ï) | 20.0842±0.1137 mas[1] |
| Distance | 162.4 ± 0.9 ly (49.8 ± 0.3 pc) |
| Absolute magnitude (MV) | +0.93[6] |
| Details | |
| Mass | 2.35[6] Mâ |
| Radius | 8[5] Râ |
| Luminosity | 37[5] Lâ |
| Surface gravity (log g) | 2.88±0.09[2] cgs |
| Temperature | 4,920±5[5] K |
| Metallicity [Fe/H] | â0.06±0.04[2] dex |
| Rotational velocity (v sin i) | 2.8±0.3[7] km/s |
| Age | 708[6] Myr |
| Other designations | |
| ν Aquarii, ν Aqr, Nu Aqr, 13 Aquarii, BDâ11 5538, HD 201381, HIP 104459, HR 8093, SAO 164182[8] | |
| Database references | |
| SIMBAD | data |
At an estimated age of 708 million years,[6] Nu Aquarii has exhausted the supply of hydrogen at its core and evolved into a giant star with a spectrum that matches a stellar classification of G8 III.[3] It has double the mass of the Sun[6] and has expanded to eight[5] times the Sun's radius. Nu Aquarii is radiating 37 times[5] the luminosity of the Sun from its photosphere at an effective temperature of 4,920 K.[5] At this heat, the star is glowing with the yellowish hue of a G-type star.[9]
Together with μ Aquarii, it is Albulaan /ËælbjÉËlÉËn/, a name derived from the Arabic term al-bulaʽÄn (Ø£ÙبÙÙعاÙ), meaning "the two swallowers". This star, along with ε Aqr (Albali) and μ Aqr (Albulaan), were al Bulaʽ (اÙبÙع)âthe Swallower.[10][11]
In Chinese, 天å£å (TiÄn LÄi 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.[12] Consequently, the Chinese name for ν Aquarii itself is 天å£åå (TiÄn LÄi Chéng shÃ, English: the Tenth Star of Celestial Ramparts).[13]