About this world
LHS 1678 b is an Earth-sized planet orbiting LHS 1678, a cool red dwarf (type M2.0V) 64.8 light-years from Earth. It is about 0.69 times the size of Earth and holds 0.35 Earth masses. It completes an orbit every 20.6 hours at 0.012 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 830 K (557 °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 2021 by transit with Transiting Exoplanet Survey Satellite (TESS). A planet crosses its star and dims it by a tiny, periodic fraction. LHS 1678 has 3 known planets; the others are LHS 1678 c and LHS 1678 d.