About this world
MOA-2009-BLG-319L b is a Neptune-like planet orbiting MOA-2009-BLG-319L, a star 23 thousand light-years from Earth. It is about 0.86 times the size of Jupiter (its size estimated from its mass) and holds 0.21 Jupiter masses.
At its size it almost certainly keeps a deep envelope of hydrogen and helium.
It was discovered in 2010 by microlensing with MOA. A foreground star's gravity magnifies a background star; a planet adds a blip.