About this world
Kepler-20 g is a Neptune-like planet orbiting Kepler-20, a yellow, Sun-like star 922 light-years from Earth. It is about 4.7 times the size of Earth (its size estimated from its mass), with at least 20 Earth masses (a minimum, measured by radial velocity). It completes an orbit every 34.9 days at 0.21 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 524 K (251 °C): far too hot for liquid water on its surface. At its size it almost certainly keeps a deep envelope of hydrogen and helium.
It was discovered in 2016 by radial velocity with Multiple Observatories. The star wobbles toward and away from us, Doppler-shifting its spectrum. Kepler-20 has 6 known planets; the others are Kepler-20 b, Kepler-20 e, Kepler-20 c, Kepler-20 f and Kepler-20 d.