Wolf 1061 and Its Three Known Planets

Wolf 1061 is a small, cool red dwarf of spectral type M3.5, lying 14 light-years from us. Its reported mass is 0.294 solar masses, and its reported radius is 0.307 solar radii. Both estimates are smaller than the Sun's. Its reported temperature is 3340 K, cooler than the Sun's. Three planets are known to orbit this star.

All three worlds were found in 2015 by the radial velocity method, which detects the wobble a planet's gravity induces in its star's motion; repeated wobbles reveal the planet and its orbital period. Each has a minimum mass, meaning a lower bound on its true mass, and each minimum mass is larger than Earth's.

Wolf 1061 b has the smallest minimum mass of the three, 1.91 Earth masses. It completes one orbit in 4.89 days, the shortest year among these planets by reported estimates. Wolf 1061 c is the middle case, with a minimum mass of 3.41 Earth masses and a period of 17.9 days, the second-shortest year of the trio by reported estimates. Wolf 1061 d is the heaviest of the three and the slowest, with a minimum mass of 7.7 Earth masses and an orbital period of 217 days, the longest year among the listed planets by reported estimates.