Gamma light from a nova https://www.mpg.de/18414085/gamma-light-from-a-nova
or the first time, it has been possible to observe the eruption of a nova in very high-energy gamma light and to follow the illumination and subsequent fading over a period of one month. The researchers combined the data from the H.E.S.S. observatory with those from the Fermi satellite and gained insights into the processes underlying the emission of gamma rays. The scientists were surprised to find that the nova apparently accelerates particles to the theoretical limit.
Particles are accelerated at these shock fronts, which collide with the dense wind