J. Baxter

At the heart of many galaxies lies an invisible beacon — a supermassive black hole. As it devours matter, it blasts a dazzling beam of gamma rays into space. If that beam points towards Earth, astronomers see a blazar — a bright but fickle point.

Seven billion years ago, a black hole at the center of a galaxy unleashed a gamma-ray flare — the most energetic form of light — with staggering power. Its light, after crossing cosmic distances, reached the MAGIC telescopes in December 2017.