About this world
TOI-1899 b is a gas giant orbiting TOI-1899, a cool red dwarf (type M0) 419 light-years from Earth. It is about 0.99 times the size of Jupiter and holds 0.67 Jupiter masses. It completes an orbit every 29.1 days at 0.15 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 378 K (105 °C): too cold 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: 2 spectroscopic observations, all of them with the James Webb Space Telescope.
It was discovered in 2020 by transit with Transiting Exoplanet Survey Satellite (TESS). A planet crosses its star and dims it by a tiny, periodic fraction.