Astronomers have discovered what they’re describing as the ‘most extreme planet ever seen’, where the surface temperature is a blistering 3,200°C.
Using the CHEOPS space telescope, researchers from the University of Bern have carried out a detailed study of the exoplanet, dubbed WASP-189b.
The planet orbits the star HD 133112, which is one of the hottest stars known to have a planetary system.
Monika Lendl, who led the study, said: “The WASP-189 system is 322 light years away and located in the constellation Libra (the weighing scales).
“WASP-189b is especially interesting because it is a gas giant that orbits very close to its host star.
“It takes less than 3 days for it to circle its star, and it is 20 times closer to it than Earth is to the Sun.”
According to the researchers, WASP-189b has one side that is permanently day time, and one that is permanently night.
Ms Lendl said: “Based on the observations using CHEOPS, we estimate the temperature of WASP-189b to be 3,200 degrees Celsius.
“Planets like WASP-189b are called ‘ultra-hot Jupiters’. Iron melts at such a high temperature, and even becomes gaseous. This object is one of the most extreme planets we know so far.”
Because the planet is so far away, the scientists can’t see it directly. Instead, the CHEOPS telescope uses high precise brightness measurements to detect planets.
Ms Lendl explained: “Because the exoplanet WASP-189b is so close to its star, its dayside is so bright that we can even measure the ‘missing’ light when the planet passes behind its star; this is called an occultation. We have observed several such occultations of WASP-189b with CHEOPS.
“It appears that the planet does not reflect a lot of starlight. Instead, most of the starlight gets absorbed by the planet, heating it up and making it shine.”