Early NuSTAR observations of the star guts exploding out of Cas A. The blue in the image is radioactive ash, while the other colors represent the materials that’s was heated by the shock wave ripping through the insides of the star. The press release is here: http://www.nustar.caltech.edu/news/nustar140219 for this paper that came out in Nature on my birthday last year. High-resolution images can be found on the NuSTAR site, which look great blown up as your screen background…