About this world
55 Cnc e is a super-Earth orbiting 55 Cnc, a yellow, Sun-like star (type G8V) 41 light-years from Earth. It is about 1.9 times the size of Earth and holds 8 Earth masses. It completes an orbit every 17.7 hours at 0.015 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 1,958 K (1,685 °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. Its atmosphere has already been studied: 23 spectroscopic observations, 16 of them with the James Webb Space Telescope.
It was discovered in 2004 by radial velocity with McDonald Observatory. The star wobbles toward and away from us, Doppler-shifting its spectrum. 55 Cnc has 5 known planets; the others are 55 Cnc b, 55 Cnc c, 55 Cnc f and 55 Cnc d.