X-ray emissions from the planet may not seem so surprising at first since Jupiter, Saturn, Uranus, and Neptune have been found to scatter such radiation from the Sun. But the data suggests that there is an additional source of unknown X-rays being generated by Uranus itself.
“Planets with lots of hydrogen in their atmosphere scatter X-rays in the same way that we think Uranus is [doing],” Affelia Wibisono, co-author of the Uranus X-ray study published in the Journal of Geophysical Research: Space Physics, and a PhD student at University College London, explained to The Register”
https://www.theregister.com/2021/04/02/uranus_xrays/
