About this world
KMT-2024-BLG-0404L c is a Neptune-like planet orbiting KMT-2024-BLG-0404L, a cool red dwarf (type M) 23.5 thousand light-years from Earth. It is about 4.3 times the size of Earth (its size estimated from its mass) and holds 17 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. KMT-2024-BLG-0404L has 2 known planets; the others are KMT-2024-BLG-0404L b.