About this world
OGLE-2017-BLG-1691L b is a sub-Neptune orbiting OGLE-2017-BLG-1691L, a star 23.8 thousand light-years from Earth. It is about 3.9 times the size of Earth (its size estimated from its mass) and holds 15 Earth masses.
At its size it almost certainly keeps a deep envelope of hydrogen and helium.
It was discovered in 2022 by microlensing with OGLE. A foreground star's gravity magnifies a background star; a planet adds a blip.