About this world
TOI-1355 b is a gas giant orbiting TOI-1355, a white A-type star (type A3V) 809 light-years from Earth. It is about 1.4 times the size of Jupiter. It completes an orbit every 2.17 days at 0.04 AU from its star, closer than Mercury is to the Sun, on a strongly elongated orbit (e = 0.22).
Its equilibrium temperature is about 2,740 K (2,467 °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 2026 by transit with Transiting Exoplanet Survey Satellite (TESS). A planet crosses its star and dims it by a tiny, periodic fraction.