From Peking University in Beijing, China; Linhua Jiang and his colleagues were studying GN-z11, the oldest known galaxy in the universe. They were using the Keck Observatory in Hawaii to look at GN-z11 when they said they saw the galaxy become hundreds of times brighter in less than 3 minutes. High-energy radiation can create an explosion in space, known as a gamma-ray burst, which has been observed in other galaxies in the past and this is what researchers this may have happened in GN-z11.

When people observe the galaxy, they see it as it appeared 13.4 billion years ago which lends to it being one of the first galaxies to be formed. Due to the universe's expansion, GN-z11 is about 32 billion light years from Earth. The gamma-ray burst would've only lasted roughly 20 seconds in real time given the distance between the galaxy and Earth. Until this was observed, the oldest gamma-ray burst occurred about 100 million years later. The significance of the GN-z11 event is that if this was a gamma-ray burst, then galaxies in the early universe were more active than previously thought.

Jiang said, "The probability to detect a gamma-ray burst [in a particular galaxy] is near to zero... If you observed a galaxy for a million years, you'd probably [only] find a few gamma-ray bursts. That's why it's so surprising." Due to the rarity of the event, researchers still aren't sure that this was a gamma-ray burst. There is a possibility that an asteroid or a rogue satellite signal that caused the light Jiang saw. However, given the duration and the brightness of what happened more than likely this was a gamma-ray burst although we won't know for sure since the event has passed.

Linhua Jiang

source:https://www.newscientist.com/article/2262665-we-may-have-seen-a-huge-explosion-in-the-oldest-galaxy-in-the-universe/#:~:text=Sign%20In%20Search-,We%20may%20have%20seen%20a%20huge%20explosion,oldest%20galaxy%20in%20the%20universe&text=An%20explosion%20of%20high%2Denergy,years%20after%20the%20big%20bang.