About this world
HD 13808 b is a sub-Neptune orbiting HD 13808, an orange dwarf (type K2V) 92.1 light-years from Earth. It is about 3.4 times the size of Earth (its size estimated from its mass), with at least 11 Earth masses (a minimum, measured by radial velocity). It completes an orbit every 14.2 days at 0.11 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 662 K (388 °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 2021 by radial velocity with La Silla Observatory. The star wobbles toward and away from us, Doppler-shifting its spectrum. HD 13808 has 2 known planets; the others are HD 13808 c.