From Nuclear Watchdogs to Cosmic Fireworks: The Vela Satellites That Sparked Gamma-Ray Astronomy

The Vela satellites, built to detect secret nuclear tests, recorded a mysterious 1967 gamma-ray flash that didn’t fit terrestrial or solar sources, initiating gamma-ray burst research. Over time, improved timing allowed precise localization, establishing bursts as cosmic in origin. BeppoSAX’s 1997 afterglow localizations linked bursts to distant galaxies and revealed two main classes—short bursts from compact mergers and long bursts from collapsing massive stars—while extraordinary events like GRB 221009A in 2022 showed bursts can outshine almost all prior records, marking gamma-ray bursts as a central field in high-energy astrophysics.