About this world
TOI-5165 b is a sub-Neptune orbiting TOI-5165, an orange dwarf (type K4) 800 light-years from Earth. It is about 3.3 times the size of Earth. It completes an orbit every 3.58 days at 0.041 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 870 K (597 °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 transit with K2. A planet crosses its star and dims it by a tiny, periodic fraction.