Astronomers have found a "hotspot" beneath the Big Dipper emitting a disproportionate number of the highest-energy cosmic rays, a discovery which may move physics toward identifying the mysterious sources of the most energetic particles in the universe.
Many astrophysicists suspect ultrahigh-energy cosmic rays are generated by active galactic nuclei, or AGNs, in which material is sucked into a supermassive black hole at the center of galaxy, while other material is spewed away in a beam-like jet known as a blazar. Another popular possibility is that the highest-energy cosmic rays come from some supernovas (exploding stars) that emit gamma rays bursts.