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, Nu Aquarii is visible to the naked eye. Its distance from Earth, as determined from parallax measurements, is around 159abbr=offNaNabbr=off. At an estimated age of 708 million years, it has evolved into a giant star with a spectrum that matches a stellar classification of G8 III. It has than double the mass of the Sun and has expanded to eight times the Sun's radius. Nu Aquarii is radiating 37-fold the luminosity of the Sun from its outer atmosphere at an effective temperature of . At this heat, the star is glowing with the yellowish hue of a G-type star.
Together with μ Aquarii, it is Albulaan, 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.
In Chinese, Chinese: 天壘城 (Chinese: 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.[1] Consequently, the Chinese name for ν Aquarii itself is Chinese: 天壘城十 (Chinese: Tiān Lěi Chéng shí, English: the Tenth Star of Celestial Ramparts).[2]