About this world
KMT-2023-BLG-1896L b is a Neptune-like planet orbiting KMT-2023-BLG-1896L, an orange dwarf (type K6V) 17.9 thousand light-years from Earth. It is about 4.2 times the size of Earth (its size estimated from its mass) and holds 16 Earth masses.
At its size it almost certainly keeps a deep envelope of hydrogen and helium.
It was discovered in 2025 by microlensing with KMTNet. A foreground star's gravity magnifies a background star; a planet adds a blip.