Astronomers using the James Webb Space Telescope have detected the coldest exoplanet ever seen, orbiting a dead star. The discovery, named WD 1856+534 b, is located about 80 light-years from Earth and orbits a white dwarf star every 1.4 days.
The planet’s temperature of -125 degrees Fahrenheit (-87 degrees Celsius) makes it the coldest exoplanet directly observed. Previous record-holders stand at around 35 degrees Fahrenheit (2 degrees Celsius).
This discovery provides new insights into how planets evolve during a star’s final stages. The data also confirm that WD 1856+534 b is a planet, rather than a brown dwarf.
The finding suggests that planets can survive the violent death of their star and move into orbits where they didn’t previously exist. This process could be key to moving planets into habitable zones around white dwarfs, where life as we know it could emerge.
Astronomer Mary Anne Limbach said, “This is compelling evidence that planets can not only survive the death of their star, but also move into orbits where we didn’t previously expect them to exist.”
The James Webb Space Telescope’s observations offer a rare opportunity to place our solar system in a broader galactic context. Future data from the telescope could reveal temperatures, ages, and masses of exoplanets similar to Jupiter and Saturn.
Limbach and her team plan to conduct another JWST observation of the WD 1856+534 system this July, which will help them understand how the planet migrated to its current close orbit around the white dwarf.
Source: https://www.space.com/astronomy/james-webb-space-telescope/james-webb-space-telescope-finds-coldest-exoplanet-ever-seen-and-it-orbits-a-dead-star