About this world
OGLE-2005-BLG-390L b is a sub-Neptune orbiting OGLE-2005-BLG-390L, a star 21.5 thousand light-years from Earth. It is about 2.2 times the size of Earth (its size estimated from its mass) and holds 5.5 Earth masses. It completes an orbit every 8.99 years at 2.6 AU from its star.
Its equilibrium temperature is about 50 K (−223 °C): too cold for liquid water on its surface. At its size it almost certainly keeps a deep envelope of hydrogen and helium.
It was discovered in 2005 by microlensing with OGLE. A foreground star's gravity magnifies a background star; a planet adds a blip.