About this world
HD 128356 b is a gas giant orbiting HD 128356, an orange dwarf (type K3V) 85.3 light-years from Earth. It is about 1.2 times the size of Jupiter (its size estimated from its mass), with at least 0.89 Jupiter masses (a minimum, measured by radial velocity). It completes an orbit every 298 days at 0.87 AU from its star, on a strongly elongated orbit (e = 0.57).
Its equilibrium temperature is about 232 K (−41 °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 2016 by radial velocity with Multiple Observatories. The star wobbles toward and away from us, Doppler-shifting its spectrum.