About this world
HD 20794 f is a sub-Neptune orbiting HD 20794, a yellow, Sun-like star (type G6V) 19.6 light-years from Earth. It is about 2.3 times the size of Earth (its size estimated from its mass), with at least 5.8 Earth masses (a minimum, measured by radial velocity). It completes an orbit every 648 days at 1.4 AU from its star, on a strongly elongated orbit (e = 0.45).
Its equilibrium temperature is about 215 K (−59 °C), which places it in the conservative habitable zone: the band where liquid water could exist on a rocky surface. At its size it almost certainly keeps a deep envelope of hydrogen and helium.
It was discovered in 2025 by radial velocity with Multiple Observatories. The star wobbles toward and away from us, Doppler-shifting its spectrum. HD 20794 has 4 known planets; the others are HD 20794 b, HD 20794 d and HD 20794 e.