On December 11, 2021, a beam of gamma rays the most energetic form of light slammed into NASA’s Swift satellite. Within 120 seconds, the satellite had swiveled toward the blast and spotted the glowing embers of a cosmic catastrophe. Ten minutes later, alerts went out to astronomers around the world. Among them was Jillian Rastinejad. A graduate student at Northwestern University. To Rastinejad and her collaborators. This gamma-ray burst looked oddly similar to an unusual burst from 2006. Rastinejad called up the Gemini Observatory in Hawai‘i and enlisted researchers there to stare deeply at the patch of sky where the burst had come from.
Cold War Brilliant Explosions
Today, Swift catches a gamma-ray burst every few days. But the Phone Number List blasts were unknown until the height of the Cold War, when they appeared out of nowhere. In the 1960s, the U.S. Air Force launched the Vela satellites to make sure the Soviet Union was abiding by a nuclear weapon test ban. If the Soviets detonated a nuclear bomb in space. The resulting flash of gamma rays — energetic waves of light as short as the nucleus of an atom — would be impossible to hide. The satellites didn’t detect any Soviet violations. But between 1969 and 1972. They did pick up 16 mysterious flashes of gamma rays that researchers at Los Alamos National Laboratory determined to be of “cosmic origin.”
A Third Act Twist
First came Rastinejad’s 51-second burst in late 2021. It looked a lot like BTB Directory a lengthy nearby burst from 2006 that, puzzlingly, appeared to lack a supernova. But with modern instruments and a deeper understanding of what to look for, Rastinejad and colleagues were able to see what astronomers in 2006 had not: The 2021 burst was followed by a dim red kilonova. That observation spurred Andrew Levan of Radboud University to revisit a mysterious 64-second burst he’d been puzzling over since 2019.