YZ Ceti is a red dwarf star in the constellation Cetus. Although it is relatively close to the Sun at just 12 light years, this star cannot be seen with the naked eye. It is classified as a flare star that undergoes intermittent fluctuations in luminosity. YZ Ceti is only about 8.5% the mass of our Sun, and is normally less than 1/5,000th as luminous.
This star is unusually close to Tau Ceti, a star of spectral class G8. The two are only about 1.6 light years apart, a little more than a third of the distance from the Sun to our nearest neighbor, Proxima Centauri.