Astronomers have made a groundbreaking discovery, detecting the coldest exoplanet ever observed, orbiting a white dwarf star 81 light-years from Earth. The gas giant, WD 1856+534 b, has a mass six times that of Jupiter and orbits its star at an average temperature of 186 K (-87 °C; -125 °F), making it the coldest known exoplanet.
The discovery was made using the James Webb Space Telescope (JWST) by an international team of researchers led by Mary Anne Limbach from the University of Michigan. The team used the JWST’s Mid-Infrared Instrument to observe the planet and confirmed its presence using the Infrared excess method.
This breakthrough is significant because it provides insight into how planets interact with and survive post-main-sequence evolution, a crucial aspect of understanding planetary stability and potential habitability. White dwarf stars offer a unique opportunity to detect and characterize colder planets due to their low luminosity, which reduces contrast challenges typically associated with direct detections.
The discovery of WD 1856+534 b also reveals that planets can survive and migrate into close orbits near the habitable zones of white dwarf stars, a finding that could have implications for the search for life beyond our solar system. The team plans to further observe the planet using JWST in 2025, with hopes of identifying additional planets and shedding light on the mysteries surrounding WD planetary systems.
This discovery is a major milestone in the characterization of exoplanets using direct imaging methods, and it marks an exciting step forward in the search for life beyond our solar system.
Source: https://www.sciencealert.com/jwst-confirms-coldest-exoplanet-ever-found-circling-its-dead-star