The source of this powerful radiation was discovered outside our galaxy, its location having been pinpointed by the European Southern Observatory’s Very Large Telescope (VLT) thanks to an extensive observation program, co-led by an astronomer from the Paris Observatory - PSL.
Gamma-ray bursts, also known by the acronym GRB, are the most energetic explosions in the Universe. They are produced during devastating events, such as the death of massive stars in powerful explosions.
They usually last from a few milliseconds to a few minutes, but in this case, the GRB 250702B signal was detected several times over the course of about a day.
At present, there is no known scenario that can fully explain this new GRB, whose true nature remains a mystery, but new observations are underway, in particular to determine its precise distance. The investigation continues...
Scientific reference :
The Day-long, Repeating GRB 250702B : A Unique Extragalactic Transient, par Andrew J. Levan et al 2025 ApJL 990 L28
DOI 10.3847/2041-8213/adf8e1