Tau Ceti e

Tau Ceti e, also called 52 Ceti e, is an unconfirmed exoplanet candidate orbiting Tau Ceti, first detected in 2012 by statistical analyses of the star's variations in radial velocity obtained using HIRES, AAPS and HARPS. Its possible properties were refined in 2017, where it was one of two planets recovered from new data, the other being Tau Ceti f. It would orbit at a distance of $0.552 AU$ (between the orbits of Venus and Mercury in the Solar System) with an orbital period of 168 days and has a minimum mass of 3.93 Earth masses. If Tau Ceti e possesses an Earth-like atmosphere, the surface temperature would be around 68 C. Based upon the incident flux upon the planet, a study by Güdel et al. (2014) speculated that the planet may lie inside the inner-boundary of the habitable zone and be a Venus-like world.

A 2021 study was unable to confirm this planet.