GJ 1061 d is the outermost of three planets around GJ 1061, a small red dwarf about 12 light-years away and one of the 20 nearest stars to the Sun, and it is the one in the star's habitable zone. The habitable zone is the range of distances where a planet could keep liquid water on its surface. GJ 1061 d orbits every 13.07 days, and the discovery team found that it receives a similar amount of energy from its star as Earth receives from the Sun.
It was discovered together with its siblings GJ 1061 b and c by the Red Dots team, led by Stefan Dreizler, after three months of nightly observations with the HARPS spectrograph in 2018. They used the radial velocity method, which detects the slight back-and-forth motion a planet's gravity gives its star. The three planets' orbits are close to a 1 to 2 to 4 ratio, and in 2025 the team used the planets' small pulls on each other, measured with new ESPRESSO data, to find their true masses. GJ 1061 d came out at about 1.55 Earth masses, assuming all three orbits lie in one plane.
The 2025 study concluded that all three planets are potentially rocky, and GJ 1061 d is the coolest, with an estimated equilibrium temperature, set by starlight alone, of about 240 kelvin. Its star is similar to Proxima Centauri but shows less activity, which improves the chances that a planet there could hold on to an atmosphere. None of the three planets passes in front of its star, so their sizes are unknown, and whether GJ 1061 d has air or water is an open question. The discovery team noted that the system is one of the best targets for future telescopes able to study the atmospheres of nearby planets directly.