About this world
HD 50554 d is a super-Earth orbiting HD 50554, a yellow-white F-type star (type F8V) 102 light-years from Earth. It is about 1.4 times the size of Earth and holds 10 Earth masses. It completes an orbit every 28.1 days at 0.18 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 651 K (378 °C): far too hot for liquid water on its surface. By the "cosmic shoreline", it has likely held on to an atmosphere.
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. HD 50554 has 3 known planets; the others are HD 50554 c and HD 50554 b.