About this world
SPECULOOS-3 b is an Earth-sized planet orbiting SPECULOOS-3, a cool red dwarf (type M6.5+/-). It is about 0.98 times the size of Earth. It completes an orbit every 17.3 hours at 0.0073 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 553 K (280 °C): far too hot for liquid water on its surface. By the "cosmic shoreline", its star has probably stripped its atmosphere away, leaving bare rock.
It was discovered in 2024 by transit with SPECULOOS Southern Observatory. A planet crosses its star and dims it by a tiny, periodic fraction.