About this world
HD 12235 b is a sub-Neptune orbiting HD 12235, a yellow, Sun-like star 104 light-years from Earth. It is about 3.2 times the size of Earth (its size estimated from its mass), with at least 10 Earth masses (a minimum, measured by radial velocity). It completes an orbit every 4.36 days at 0.054 AU from its star, closer than Mercury is to the Sun, on a strongly elongated orbit (e = 0.38).
Its equilibrium temperature is about 1,667 K (1,394 °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 2022 by radial velocity with Multiple Observatories. The star wobbles toward and away from us, Doppler-shifting its spectrum. HD 12235 has 2 known planets; the others are HD 12235 c.