About this world
LTT 9779 b is a Neptune-like planet orbiting LTT 9779, a yellow, Sun-like star (type G7V) 262 light-years from Earth. It is about 4.7 times the size of Earth and holds 29 Earth masses. It completes an orbit every 19 hours at 0.017 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 1,978 K (1,705 °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: 5 spectroscopic observations, 2 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.