Scientists may soon observe the earliest light in our universe

For decades, astronomers have been hoping to understand how the universe evolved after the Big Bang 13.8 billion years ago. To do so, they would have to observe the universe’s origin. Now, an international, multidisciplinary research team led by the University of Cambridge may do just that. 

The researchers developed a method that will allow them to observe and study some of the first stars that existed roughly 378,000 years after the Big Bang.

“At the time when the first stars formed, the Universe was mostly empty and composed mostly of hydrogen and helium,” said study lead author Dr. Eloy de Lera Acedo from Cambridge’s Cavendish Laboratory.

“Because of gravity, the elements eventually came together and the conditions were right for nuclear fusion, which is what formed the first stars. But they were surrounded by clouds of so-called neutral hydrogen, which absorb light really well, so it’s hard to detect or observe the light behind the clouds directly.”

The new methodology includes the REACH (Radio Experiment for the Analysis of Cosmic Hydrogen). This technique allows astronomers to observe early stars via their relationships with hydrogen clouds. The newly developed approach produces higher quality observations and is more reliable.

“Our method jointly analyzes data from multiple antennas and across a wider frequency band than equivalent current instruments. This approach will give us the necessary information for our Bayesian data analysis,” said Dr. de Lera Acedo.

“In essence, we forgot about traditional design strategies and instead focused on designing a telescope suited to the way we plan to analyse the data – something like an inverse design.”

REACH is anticipated to produce its first observations later this year. The research may ultimately confirm the findings of an earlier study that claims to have witnessed the earliest light.

“We are extremely excited to see how well the system will perform, and have full confidence we’ll make that elusive detection.” said Professor de Villiers, co-lead of the project at the University of Stellenbosch in South Africa.

“If we can confirm that the signal found in that earlier experiment really was from the first stars, the implications would be huge,” said Dr. de Lera Acedo.

 The study is published in the journal Nature Astronomy.

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By Erin Moody , Earth.com Staff Writer