The James Webb Space Telescope (JWST) has confirmed WD 1856+534 b as the coldest exoplanet ever observed. This gas giant, approximately six times the mass of Jupiter, orbits a white dwarf star located 81 light-years from Earth.
Observations using JWST's Mid-Infrared Instrument (MIRI) revealed the exoplanet has an average temperature of 186 K (-87°C; -125°F). This makes it the coldest exoplanet whose light has ever been directly observed.
This discovery, made in April 2025, provides the first direct evidence that planets can endure and migrate into close orbits near the habitable zones of white dwarfs. Further JWST observations are scheduled for 2025 to search for additional planets in the system and analyze the atmosphere of WD 1856+534 b.