Astronomers have discovered direct evidence that gamma-ray bursts, the most energetic events in the universe, are linked to supernovas, the explosive death of massive stars.
On March 29, NASA’s High-Energy Transient Explorer satellite detected one of the closest gamma-ray bursts on record. For half a minute, the burst outshone the gamma rays from all the rest of the universe.
Observations of the burst’s afterglow began a half-day later. In early April, astronomers saw signs of a supernova explosion superimposed on the afterglow. Those signs included an upswing in the fading light’s intensity as well as the presence of heavy elements, such as iron, that can be forged only in supernovas.
