K2-148b
K2-148b is a confirmed Super-Earth, probably rocky, closely orbiting a small orange dwarf star. It is the innermost of three Super-Earths around the star K2-148, which is in a wide binary pair with the M0.5V red dwarf EPIC 220194953. K2-148b is the smallest planet of the system, at about a third larger than Earth, and could be terrestrial in nature. However, the three planets do not exhibit significant transit timing variations, implying that they could have relatively low masses. The planet was validated in early 2018 by Hirano "et al." and is too hot for known life.
Kepler-186f
The nearest-to-Earth-size planet in a habitable zone previously known was Kepler-62f with 1.4 Earth radii. Kepler-186f orbits an M-dwarf star, while Kepler-62f orbits a K-type star. A study of atmospheric evolution in Earth-size planets in habitable zones of G-Stars (a class containing the Sun, but not Kepler-186) suggested that 0.8–1.15 R is the size range for planets small enough to lose their initial accreted hydrogen envelope but large enough to retain an outgassed secondary atmosphere such as Earth's.