About this world
TIC 390586021 b is a sub-Neptune orbiting TIC 390586021, an orange dwarf 374 light-years from Earth. It is about 2.9 times the size of Earth. It completes an orbit every 2.75 days at 0.033 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 934 K (661 °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.