James Webb telescope discovers most distant supernova ever seen

The James Webb Space Telescope has discovered the oldest and most distant supernova ever seen — a stellar explosion that took place when the universe was just 1.8 billion years old.

The ancient starburst was uncovered among 80 others in a patch of sky that, from our perspective on Earth, is about the width of a grain of rice held at arm's length. 

Supernovae are transient objects, as their brightness changes over time. This makes the new batch of distant star explosions especially exciting, as studying them could provide key insights into unresolved questions of how the early universe grew. The researchers presented their findings June 10 at the 244th meeting of the American Astronomical Society in Madison, Wisconsin. 

"We're essentially opening a new window on the transient universe," Matthew Siebert, an astronomer who is leading the spectroscopic analysis of the supernovas, said in a statement. "Historically, whenever we've done that, we've found extremely exciting things — things that we didn't expect."

There are two main categories of supernova: core collapse and thermonuclear runaway supernovae. 

Explosions in the first category occur when stars with masses at least eight times bigger than our sun run out of fuel and collapse in on themselves, before expanding outward again in a gigantic explosion. 

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