Giant exoplanet WD 1856 b suggests planets can survive star death

Researchers from the University of St Andrews have discovered that the death of a star does not necessarily result in the destruction of all planets within its system. According to a study published in the journal Nature, observations from the James Webb Space Telescope of the exoplanet WD 1856 b suggest that giant planets can survive the transition of their host star into a white dwarf.

Located approximately 80 light-years from Earth, WD 1856 b is a Jupiter-sized planet with a mass between four and 11 times greater than Jupiter. While it currently orbits its white dwarf star every 1.4 days at a distance of only 3 million kilometers, thermal analysis indicates the planet likely remained in a distant, safe orbit for billions of years after the star's red giant phase. Gravitational interactions eventually triggered a migration toward the inner system, generating internal heat through tidal forces.

The study also marked the first characterization of an atmosphere orbiting a dead star, revealing the presence of clouds, haze, and hydrocarbons, such as methane. These findings provide insight into the potential future of our own Solar System; while the Sun's eventual transition into a red giant will likely destroy Mercury, Venus, and possibly Earth, outer gas giants like Jupiter or Saturn may survive.