Alpha Hydri

Alpha Hydri (α Hyi, α Hydri) is a star in the constellation Hydrus. It is sometimes informally known as the Head of Hydrus. It should not be confused with Alpha Hydrae (Alphard) in the constellation Hydra. Alpha Hydri is one of only three stars in the constellation Hydrus that is above the fourth visual magnitude. This star can be readily located as it lies to the south and west of the prominent star Achernar in the constellation Eridanus.

Alpha Hydri belongs to spectral class F0V and has apparent magnitude +2.9. It is 1.8 times the radius of the Sun, about 810 million years old, and is approximately 71 light years from Earth. The space velocity components of this star are U = −14, V = −14 and W = -2 km/s. Alpha Hydri emits X-rays similar to Altair.

In the Alliance-Union universe created by C. J. Cherryh. Home star system of the Majat, an insectoid race that features prominently in the novel Serpent's Reach (1980).