About this world
Kepler-139 f is a Neptune-like planet orbiting Kepler-139, a yellow, Sun-like star 1.28 thousand light-years from Earth. It is about 0.6 times the size of Jupiter (its size estimated from its mass) and holds 0.11 Jupiter masses. It completes an orbit every 355 days at 1 AU from its star.
Its equilibrium temperature is about 280 K (7 °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 timing variations with Multiple Observatories. Pulsar, eclipse or transit timings drift as an unseen companion tugs on them. Kepler-139 has 5 known planets; the others are Kepler-139 d, Kepler-139 b, Kepler-139 c and Kepler-139 e.