About this world
TOI-5789 e is a sub-Neptune orbiting TOI-5789, an orange dwarf (type K1V) 66.7 light-years from Earth. It is about 3.4 times the size of Earth (its size estimated from its mass), with at least 12 Earth masses (a minimum, measured by radial velocity). It completes an orbit every 63 days at 0.29 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 424 K (151 °C): far too hot for liquid water on its surface. At its size it almost certainly keeps a deep envelope of hydrogen and helium.
It was discovered in 2026 by radial velocity with Multiple Observatories. The star wobbles toward and away from us, Doppler-shifting its spectrum. TOI-5789 has 4 known planets; the others are TOI-5789 b, TOI-5789 c and TOI-5789 d.