About this world
HD 3167 c is a sub-Neptune orbiting HD 3167, an orange dwarf (type K0V) 154 light-years from Earth. It is about 3 times the size of Earth and holds 11 Earth masses. It completes an orbit every 29.8 days at 0.18 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 567 K (294 °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: 4 spectroscopic observations.
It was discovered in 2016 by transit with K2. A planet crosses its star and dims it by a tiny, periodic fraction. HD 3167 has 4 known planets; the others are HD 3167 b, HD 3167 d and HD 3167 e.