About this world
HD 21749 c is an Earth-sized planet orbiting GJ 143, an orange dwarf (type K4V) 53.2 light-years from Earth. It is about 0.98 times the size of Earth and holds 1.4 Earth masses. It completes an orbit every 7.79 days at 0.069 AU from its star, closer than Mercury is to the Sun, on a strongly elongated orbit (e = 0.25).
Its equilibrium temperature is about 728 K (455 °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 2019 by transit with Transiting Exoplanet Survey Satellite (TESS). A planet crosses its star and dims it by a tiny, periodic fraction. GJ 143 has 2 known planets; the others are GJ 143 b.