About this world
HD 141399 d is a gas giant orbiting HD 141399, an orange dwarf (type K0) 121 light-years from Earth. It is about 1.2 times the size of Jupiter (its size estimated from its mass), with at least 1.2 Jupiter masses (a minimum, measured by radial velocity). It completes an orbit every 2.93 years at 2.1 AU from its star.
Its equilibrium temperature is about 220 K (−53 °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 2014 by radial velocity with Multiple Observatories. The star wobbles toward and away from us, Doppler-shifting its spectrum. HD 141399 has 4 known planets; the others are HD 141399 b, HD 141399 c and HD 141399 e.