About this world
HIP 38594 b is a sub-Neptune orbiting HIP 38594, a cool red dwarf (type M0) 58 light-years from Earth. It is about 2.8 times the size of Earth (its size estimated from its mass), with at least 8.1 Earth masses (a minimum, measured by radial velocity). It completes an orbit every 60.7 days at 0.26 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 308 K (35 °C), which places it in the optimistic 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 2020 by radial velocity with Multiple Observatories. The star wobbles toward and away from us, Doppler-shifting its spectrum. HIP 38594 has 2 known planets; the others are HIP 38594 c.