Kepler-1649c: an Earth twin with a short-tempered host star

The Kepler telescope has already been shut down, but astronomers are still finding new exoplanets in its data. Kepler-1649c, which is 300 light-years from Earth, is one of these recently discovered treasures. The planet was overlooked by the first, automated search through the data. The rocky planet has one very intriguing characteristic: it is the most Earth-like exoplanet discovered to date.

Kepler-1649c is only 1.06 times larger than Earth. Its host star supplies it with about...