About this world
HD 42618 b is a sub-Neptune orbiting HD 42618, a yellow, Sun-like star (type G4V) 79.4 light-years from Earth. It is about 3.9 times the size of Earth (its size estimated from its mass), with at least 14 Earth masses (a minimum, measured by radial velocity). It completes an orbit every 150 days at 0.55 AU from its star.
Its equilibrium temperature is about 337 K (64 °C): too cold 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.