About this world
TOI-1227 b is a Neptune-like planet orbiting TOI-1227, a cool red dwarf (type M4.5V-M) 328 light-years from Earth. It is about 0.85 times the size of Jupiter. It completes an orbit every 27.4 days at 0.089 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 244 K (−29 °C): too cold 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.