About this world
TOI-4010 c is a Neptune-like planet orbiting TOI-4010, an orange dwarf (type KV) 579 light-years from Earth. It is about 5.9 times the size of Earth and holds 20 Earth masses. It completes an orbit every 5.41 days at 0.058 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 907 K (634 °C): far too hot for liquid water on its surface. At its size it almost certainly keeps a deep envelope of hydrogen and helium. Its atmosphere has already been studied in one spectroscopic observation by the James Webb Space Telescope.
It was discovered in 2023 by transit with Transiting Exoplanet Survey Satellite (TESS). A planet crosses its star and dims it by a tiny, periodic fraction. TOI-4010 has 4 known planets; the others are TOI-4010 b, TOI-4010 d and TOI-4010 e.