The Turbulent, High-Energy Sky Is Keeping NuSTAR Busy
NuSTAR has been busy studying the most energetic phenomena in the universe. Recently, a few high-energy events have sprung up, akin to "things that go bump in the night." When one telescope catches a sudden outpouring of high-energy light in the sky, NuSTAR and a host of other telescopes stop what they were doing and take a better look.
For example, in early April, the blazar Markarian 421 had an episode of extreme activity, brightening by more than 50 times its typical level. Blazars are a special class of galaxies with accreting, or "feeding," supermassive black holes at their centers. As the black holes feed, they light up, often ejecting jets of material. When the jets are pointing toward Earth, they are called blazars. By using telescopes sensitive to a range of energies to study how blazars vary, astrophysicists gain insight into black hole feeding processes and the physical conditions near the black hole.