Tau Ceti

Lore & Background

The name 'Tau Ceti' is the Bayer designation for this star, established in 1603 as part of German celestial cartographer Johann Bayer's Uranometria star catalogue. In the catalogue of stars in the Calendarium of Al Achsasi al Mouakket, written at Cairo about 1650, this star was designated Thālith al Naʽāmāt, translated into Latin as Tertia Struthionum, meaning the third of the ostriches. In Chinese astronomy, the 'Square Celestial Granary' refers to an asterism consisting of τ Ceti, ι Ceti, η Ceti, ζ Ceti, θ Ceti and 57 Ceti; the Chinese name for τ Ceti itself is 'the Fifth Star of Square Celestial Granary'.

Reader's Guide

Tau Ceti is a high-proper-motion star, moving at an angular rate across the celestial sphere. Its radial velocity is about −17 km/s, indicating it is moving toward the Sun. The star will make its closest approach to the Sun in about 43,000 years, when it comes to within 3.25 pc. The space velocity relative to the Sun can be used to compute an orbital path through the Milky Way; it has a mean galacto-centric distance and an orbital eccentricity of 0.22.

Observations have detected more than ten times as much dust surrounding Tau Ceti as is present in the Solar System. Because of its debris disk, any planet orbiting Tau Ceti would face far more impact events than present day Earth. Despite this hurdle to habitability, its solar analog characteristics have led to widespread interest in the star. Given its stability, similarity and relative proximity to the Sun, Tau Ceti is consistently listed as a target for the search for extraterrestrial intelligence (SETI).

Did You Know?

• Tau Ceti has only about 78% of the Sun's mass and 55% of its luminosity.
• The star is metal-deficient, with an atmospheric metallicity of about a third the solar abundance.
• A terrestrial planet would need to orbit Tau Ceti at a distance of about 0.7 AU to match Earth's solar insolation.