Astronomers have confirmed the existence of a gas giant exoplanet, WD 1856+534 b, orbiting a white dwarf star as the coldest planet ever detected. The discovery was made using the James Webb Space Telescope (JWST) and provides valuable insights into the fate of planetary systems after stellar death.
In 2020, researchers initially identified the exoplanet, located 81 light-years from Earth, with its massive size comparable to Jupiter’s. Since then, an international team of scientists led by Mary Anne Limbach has been studying the planet using JWST data.
Their analysis revealed that WD 1856+534 b orbits a white dwarf star and has an average temperature of 186 K (-87°C; -125°F), confirming it as the coldest exoplanet ever observed. This discovery is significant, as it provides evidence that planets can survive close to their host stars in later stages of stellar evolution.
The team’s findings also suggest that the exoplanet was perturbed into its current orbit near the habitable zone of the white dwarf star. Future observations by JWST are scheduled for 2025 and will help identify additional planets in this system, potentially shedding light on the planet’s past.
This groundbreaking discovery is a testament to the James Webb Space Telescope’s capabilities in studying exoplanets and understanding their formation, composition, and potential habitability.
Source: https://phys.org/news/2025-04-webb-coldest-planet-orbiting-white.html