About this world
TOI-4311 c is a sub-Neptune orbiting TOI-4311, an orange dwarf (type K) 440 light-years from Earth. It is about 2.5 times the size of Earth and holds 14 Earth masses. It completes an orbit every 15.1 days at 0.11 AU from its star, closer than Mercury is to the Sun, on a strongly elongated orbit (e = 0.22).
Its equilibrium temperature is about 671 K (398 °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 Transiting Exoplanet Survey Satellite (TESS). A planet crosses its star and dims it by a tiny, periodic fraction. TOI-4311 has 2 known planets; the others are TOI-4311 b.