The star appears stable, with little stellar variation, and is metal-deficient (low in elements other than hydrogen and helium) relative to the Sun.

[nb 2][9] Observations have detected more than ten times as much dust surrounding Tau Ceti as is present in the Solar System.

[13] Because of its debris disk, any planet orbiting Tau Ceti would face far more impact events than present day Earth.

Note that those planetary candidates have been contested[14] and recent discoveries about the stellar inclination cast doubt about the terrestrial nature of these worlds.

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).

[20] The proper motion of a star is its rate of movement across the celestial sphere, determined by comparing its position relative to more distant background objects.

By comparing the spectrum to computed models of stellar evolution, the age, mass, radius and luminosity of Tau Ceti can be estimated.

By this means the rotation period for Tau Ceti is estimated to be 34 d.[32] Due to the Doppler effect, the rotation rate of a star affects the width of the absorption lines in the spectrum (light from the side of the star moving away from the observer will be shifted to a longer wavelength; light from the side moving towards the observer will be shifted toward a shorter wavelength).

The relatively low rotational velocity measurements may indicate that Tau Ceti is being viewed from nearly the direction of its pole.

The interstellar medium of dust and gas from which stars form is primarily composed of hydrogen and helium with trace amounts of heavier elements.

As nearby stars continually evolve and die, they seed the interstellar medium with an increasing portion of heavier elements.

[35] The amount of metallicity in a star is given in terms of the ratio of iron (Fe), an easily observed heavy element, to hydrogen.

[33] Alternatively it has been suggested that the star could be in a low-activity state analogous to a Maunder Minimum—a historical period, associated with the Little Ice Age in Europe, when sunspots became exceedingly rare on the Sun's surface.

[39][40] Spectral line profiles of Tau Ceti are extremely narrow, indicating low turbulence and observed rotation.

[2] Principal factors driving research interest in Tau Ceti are its proximity, its Sun-like characteristics, and the implications for possible life on its planets.

For categorization purposes, Hall and Lockwood report that "the terms 'solarlike star', 'solar analog', and 'solar twin' [are] progressively restrictive descriptions".

[45] Tau Ceti fits the second category, given its similar mass and low variability, but relative lack of metals.

In 1988, radial-velocity observations ruled out any periodical variations attributable to massive planets around Tau Ceti inside of Jupiter-like distances.

[50] If hot Jupiters were to exist in close orbit, they would likely disrupt the star's habitable zone; their exclusion was thus considered positive for the possibility of Earth-like planets.

[43] They confirmed Tau Ceti e and f as candidates but failed to consistently detect planets b (which may be a false negative), c (whose weakly defined apparent signal was correlated to stellar rotation), and d (which did not show up in all data sets).

In 2019, a paper published in Astronomy & Astrophysics suggested that Tau Ceti could have a Jupiter or super-Jupiter based on a tangential astrometric velocity of around 11.3 m/s.

So, for example, if as estimated in the Korolik et al 2023 study Tau Ceti has a pole-on inclination of around 7 degrees, and the postulated planets do as well, then those planets' orbits would be verging on instability within just a 10 million year timeframe, and therefore it is extremely unlikely they would have survived for the billions of years that make up the lifetime of the star system.

[14] In 2004, a team of UK astronomers led by Jane Greaves discovered that Tau Ceti has more than ten times the amount of cometary and asteroidal material orbiting it than does the Sun.

[63] This result puts a damper on the possibility of complex life in the system, because any planets would suffer from large impact events roughly ten times more frequently than present day Earth.

Greaves noted at the time of her research that "it is likely that [any planets] will experience constant bombardment from asteroids of the kind believed to have wiped out the dinosaurs".

[63] The debris disk was discovered by measuring the amount of radiation emitted by the system in the far infrared portion of the spectrum.

The lack of infrared radiation from the warmer parts of the disk near Tau Ceti implies an inner cut-off at a radius of 10 AU.

It was run by the astronomer Frank Drake, who selected Tau Ceti and Epsilon Eridani as the initial targets.

In 2002, astronomers Margaret Turnbull and Jill Tarter developed the Catalog of Nearby Habitable Systems (HabCat) under the auspices of Project Phoenix, another SETI endeavour.

[70] The next year, Turnbull would further refine the list to the 30 most promising systems out of 5000 within 100 light-years from the Sun, including Tau Ceti; this will form part of the basis of radio searches with the Allen Telescope Array.