About this world
pi Men c is a sub-Neptune orbiting HD 39091, a yellow, Sun-like star (type G0V) 59.6 light-years from Earth. It is about 2 times the size of Earth and holds 3.6 Earth masses. It completes an orbit every 6.27 days at 0.068 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 1,170 K (897 °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 2018 by transit with Transiting Exoplanet Survey Satellite (TESS). A planet crosses its star and dims it by a tiny, periodic fraction. HD 39091 has 3 known planets; the others are pi Men d and HD 39091 b.