In October 2022, telescopes picked up a flash of high-intensity gamma rays from a galaxy 1.9 billion light years away. The cosmic explosion, aptly dubbed the Brightest of All Time (BOAT), was caused by a highly massive star collapsing and the subsequent birth of a black hole. The initial flash was followed by a slow-fading afterglow of light across frequencies.

Dr Hendrik Van Eerten of the Department of Physics joined an international team to try and understand what caused the gamma-ray burst shone so brightly and why its afterglow faded curiously slowly.

Their findings, which have been published in the prestigious journal Science Advances, suggest the initial burst was angled directly at the Earth accounting for the brightness of the blast, and it dragged along an unusually large amount of stellar material in its wake.

Dr Van Eerten co-led the theoretical analysis of the explosion’s unusual afterglow.

‘Our work clearly shows that the gamma-ray burst (GRB) had a unique structure, with observations gradually revealing a narrow jet embedded within a wider gas outflow where an isolated jet would normally be expected,’ he said.

Their mathematical model helps not just to understand this event but also helps explain previous brightness record holders that have baffled astronomers.

‘An exceptional class of events appears to exist that are both extreme and manage to mask the directed nature of their gas flow,’ said Hendrik. ‘Future study into the magnetic fields that launch the jet and into the massive stars that host them should help reveal why these GRBs are so rare.’

The explosion was so bright and so close to Earth, it offers astrophysicists a once-in-a-thousand-year opportunity to explore some of the most fundamental questions surrounding gamma-ray bursts – from the formation of black holes to tests of dark matter models.