James Webb telescope ‘will see the universe’s first stars’

“If that galaxy shown to be 300 million years old is true then big galaxies had already formed,” he said.

“Stars had to form way before that. So I’m guessing [the first stars may have emerged] between 50 to 100 million years after the big bang. That would be my guess.

“That’s quite a ways back so hopefully we can see this.”

In the very infancy of the universe, there is a certain criteria that must be met before stars can form. First, the scattered gas from the big bang must cool down to a star-forming temperature and secondly, the chaotic gaseous debris needs to aggregate and become denser.

Both of these processes take time, but exactly how long remains a mystery. It is one Prof Conselice hopes Webb can also help shed some light on.

First stars would be ‘huge, short-lived stellar beasts’

He says the first stars to ever exist would be huge, short-lived stellar beasts that burnt hot and bright for a short period of time before exploding violently in a supernova.

“These big high mass stars, which is what the theory suggests, should blow up in a massive supernova,” he said.

“So, we should be able to see the explosion of stars happening in the early universe. So that’s something that people including our team is looking for. That’ll be spectacular, and I think we’ll find it actually.”

Prof Conselice has been working on James Webb for around 20 years since his days as a student at CalTech and now leads a project looking at the earliest galaxies to ever form.

His team has a year of exclusivity on this avenue of JWST research which he hopes will reduce, and potentially eradicate, the current “dark ages” which lie beyond the scope of Hubble, the long-serving telescope which has been usurped as the world’s most powerful telescope by Webb.

“There’s still a lot of things we don’t know about galaxies, even from the halfway point of the universe backwards,” he said.

“Hubble is filled in some of it, but there’s a lot there that we still need to understand.”