What makes the most powerful space explosion special?

Surveys looking for space explosions in October 2022 began to go off like frogs in socks.

The cause? The largest known blast of gamma radiation was emitted by an object located 2.4 billion light-years away.

The event, known as GRB 221009A, was so strong that it rocked Earth's outer atmosphere. It recorded an unprecedented 18 teraelectronvolts.

Science Alert subsequently discovered that the event, also known as the BOAT (Brightest of All Time), was the cataclysmic demise of a big star that gave rise to a black hole.

The details of this explosion have now been disclosed by a new examination of the evolving light. 

The latest finding suggests that, astonishingly, the BOAT was quite ordinary — something we did not anticipate — despite its gamma-ray fury.

"It's not any brighter than previous supernovae," says astrophysicist Peter Blanchard of Northwestern University in the US.

"It looks fairly normal in the context of other supernovae associated with less energetic gamma-ray bursts [GRBs]. You might expect that the same collapsing star producing a very energetic and bright GRB would also produce a very energetic and bright supernova."

"But it turns out that's not the case. We have this extremely luminous GRB, but a normal supernova," he said.