Alpha Ceti, , also known as Menkar or Menkab, is a star in the constellation of Cetus. It is an old and dying star, long past the hydrogen and perhaps even past the helium stage of its stellar evolution. It is currently a red giant star but as it begins to burn its carbon core it will likely become highly unstable before finally shedding its outer layers and forming a planetary nebula, leaving a relatively large white dwarf remnant. The name Menkar derives from the Arabic word 'manhar' (of Cetus the Whale).

In Star Trek, the Ceti Alpha system was a star system located in the Mutara sector. Ceti Alpha V was a "habitable, although a bit savage, somewhat inhospitable" planet chosen by Captain Kirk to resettle Khan Noonien Singh and the crew of the Botany Bay after their attempted takeover of the Enterprise in 2267. (TOS: "Space Seed") Six months later, Ceti Alpha VI exploded, shifting Ceti Alpha V's orbit and rendering the latter planet incapable of supporting complex life. This was discovered when the USS Reliant visited the system in 2285. (Star Trek II: The Wrath of Khan)