Earth-sized exoplanet discovered around ultracool dwarf star

View larger. | Artist’s concept of Earth-sized exoplanet SPECULOOS-3 b. The SPECULOOS project in Belgium helped an international team of astronomers discover the planet, 55 light-years from Earth. SPECULOOS-3 is only the 2nd planetary system found so far around an ultracool dwarf star. The other is the famous TRAPPIST-1 system. Image via NASA/ JPL-Caltech.

• Astronomers with the SPECULOOS project discovered an Earth-sized exoplanet orbiting an ultracool dwarf star. It’s only the second planetary...