Summary:

- Astronomers have discovered a remarkable cosmic explosion in decades-old X-ray data from the 1990s, which they believe could be the result of a neutron star merger or the birth of a black hole.
- The event, dubbed AT2023dqr, was initially detected as a bright X-ray flare that lasted for several months, and it is believed to have occurred approximately 8.5 billion light-years from Earth.
- The discovery of this event could provide valuable insights into the processes that lead to the formation of black holes and the nature of extreme cosmic events, contributing to our understanding of the universe.