天囷七

鲸鱼座ν，又名BD+04 418，HD 16161、SAO 110635、HR 754，是鲸鱼座的一颗恒星，视星等为4.86，位于银经164.48，银纬-48.67，其B1900.0坐标为赤经2h 30m 37.5s，赤纬+5° -48.67′ 25″。

Nu Ceti is a binary star system in the equatorial constellation of Cetus. Its name is a Bayer designation that is Latinized from ν Ceti, and abbreviated ν Ceti or ν Cet. This system is visible to the naked eye as a faint point of light with a combined apparent visual magnitude of 4.86. It is located approximately 340 light years distant from the Sun, based on parallax measurements, and is drifting further away with a radial velocity of 4.8 km/s. Nu Ceti is believed to be part of the Ursa Major stream of co-moving stars.

In Chinese, 天囷 (Tiān Qūn), meaning Circular Celestial Granary, refers to an asterism consisting of α Ceti, κ¹ Ceti, λ Ceti, μ Ceti, ξ¹ Ceti, ξ² Ceti, ν Ceti, γ Ceti, δ Ceti, 75 Ceti, 70 Ceti, 63 Ceti and 66 Ceti. Consequently, the Chinese name for ν Ceti itself is "the Seventh Star of Circular Celestial Granary", Tiān Qūn Qī.

The primary, designated component A, forms a single-lined spectroscopic binary with an orbital period of 1.96 years and an eccentricity of 0.27. The visible component is a G-type giant star, currently on the horizontal branch, with a stellar classification of G8III. In addition to the spectroscopic companion there is a visual companion star which shares a common proper motion with Nu Ceti A, designated component B; an F-type main-sequence star with a class of F7V and a 9.08 apparent visual magnitude located 8.0 arcsec away. It was discovered by Struve.