About this world
HD 109833 b is a sub-Neptune orbiting HD 109833, a yellow, Sun-like star 259 light-years from Earth. It is about 2.9 times the size of Earth. It completes an orbit every 9.19 days at 0.088 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 786 K (513 °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 transit with Transiting Exoplanet Survey Satellite (TESS). A planet crosses its star and dims it by a tiny, periodic fraction. HD 109833 has 2 known planets; the others are HD 109833 c.