In a recent beanbag, we focused on how Ursula K. Le Guin chose Tau Ceti as the home star system for the worlds Anarres and Urras in her 1974 novel The Dispossessed. Tau Ceti features prominently in other fictional universes including a number of mentions in Star Trek, and of course, it is the target system of the mission to save Earth (and Erid) in Project Hail Mary.

Tau Ceti is a star only 12 light-years from our solar system with a spectral type of G8V, similar to the Sun’s classification of G2V. G-type stars tend to have strong ionized calcium absorption lines (for more on spectroscopy, see this prior beanbag); this is related to their temperatures ranging between about 5200 and 6000 Kelvin. Both Tau Ceti and the Sun are main sequence stars, actively in the process of fusing hydrogen to helium in their cores.

Considered a nearby solar analog, Tau Ceti does differ from our local star in a few ways. Tau Ceti is less massive, around 78% of the Sun’s mass, and it has a much lower metallicity. This relative shortage of heavy metals, and especially the lower abundance of iron, suggests that Tau Ceti is older than our Sun.

Tau Ceti’s proximity and spectral similarity to the Sun make it an appealing system in the Search for Extraterrestrial Intelligence (SETI). Project Ozma, an early SETI experiment using the National Radio Astronomy Observatory in Green Bank, West Virginia, searched for signals of life from the direction of both Tau Ceti and Epsilon Eridani. More recently, a number of exoplanet candidates have been proposed in the Tau Ceti system, though all such planets remain unconfirmed.