About this world
DMPP-4 b is a sub-Neptune orbiting DMPP-4, a yellow-white F-type star (type F5-F8V) 82.6 light-years from Earth. It is about 3.5 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 3.5 days at 0.049 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 1,646 K (1,373 °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 2023 by radial velocity with Multiple Observatories. The star wobbles toward and away from us, Doppler-shifting its spectrum.