About this world
TOI-4336 A b is a sub-Neptune orbiting TOI-4336 A, a cool red dwarf (type M3.5V) 73.5 light-years from Earth. It is about 2.1 times the size of Earth and holds 3.3 Earth masses. It completes an orbit every 16.3 days at 0.085 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 309 K (36 °C): too cold for liquid water on its surface. By the "cosmic shoreline", it has likely held on to an atmosphere. Its atmosphere has already been studied: 2 spectroscopic observations, all of them with the James Webb Space Telescope.
It was discovered in 2024 by transit with Transiting Exoplanet Survey Satellite (TESS). A planet crosses its star and dims it by a tiny, periodic fraction. TOI-4336 A has 2 known planets; the others are TOI-4336 A c.