About this world
Kepler-309 b is a super-Earth orbiting Kepler-309, a cool red dwarf (type M0V) 1.78 thousand light-years from Earth. It is about 1.6 times the size of Earth. It completes an orbit every 5.92 days at 0.059 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 531 K (258 °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 2014 by transit with Kepler. A planet crosses its star and dims it by a tiny, periodic fraction. Kepler-309 has 2 known planets; the others are Kepler-309 c.