About this world
TIC 434398831 c is a Neptune-like planet orbiting TIC 434398831, a yellow, Sun-like star (type G4V) 708 light-years from Earth. It is about 5.6 times the size of Earth. It completes an orbit every 6.21 days at 0.066 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 1,050 K (777 °C): far too hot for liquid water on its surface. At its size it almost certainly keeps a deep envelope of hydrogen and helium.
It was discovered in 2025 by transit with Transiting Exoplanet Survey Satellite (TESS). A planet crosses its star and dims it by a tiny, periodic fraction. TIC 434398831 has 2 known planets; the others are TIC 434398831 b.