Astronomers detect signal from earliest stars in the universe

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It's causing hydrogen to start absorbing the background radiation, so you start seeing it in silhouette, at particular radio frequencies.

"Stars form when gas - mostly hydrogen - has cooled and becomes subject to fluctuations, and pieces of it start to collapse", he said. "If it's true, this is major news", says Saleem Zaroubi, a cosmologist at the University of Groningen in the Netherlands. Meanwhile, two teams of researchers operating instruments similar to Bowman's will attempt to confirm the cosmic dawn signal.

The aftermath of the Big Bang-the moment our universe exploded into existence about 13.8 billion years ago-was a little anticlimactic. When this light interacted with hydrogen atoms, it would absorb CMB photons, leaving a signal in radio frequencies; an indication that stars were forming. "And if they both see the same thing, then, 'Voila!'" he says.

A timeline of the universe, updated with results from today's study.

Stars are our constant companions in the night sky, but seas of twinkling lights weren't always a feature of the cosmos. But astronomers have long hoped to see it indirectly: the light would have subtly shifted the behaviour of the hydrogen that once filled the space between stars.

Because telescopes can not see them, though, astronomers have been hunting for indirect evidence, such as a tell-tale change in the background electromagnetic radiation that permeates the Universe, called the Cosmic Microwave Background (CMB). The faint hydrogen gas signals were picked up by a table-sized radio antenna - EDGES (Experiment to Detect Global EoR Signature) - located in Australia. They were probably hotter and simpler than modern stars, Dr. Ellis and Bowman said. And despite being a puny 0.1% drop in the radiation, it was still twice the magnitude predicted.

Those new experiments should be coming online in the coming years as well. That was where they installed their antennas. "When you're driving in the vehicle, you don't want to be changing the station all the time", Bowman said.

It's not possible to get a good look at the Big Bang.

For decades, teams of scientists have been chasing-in fact, racing-to detect the signatures of these first stars.

These are radio waves produced by the Big Bang. Eventually, the stars exploded and created heavier elements like oxygen and carbon, the ingredients necessary for life.

We use the speed of light when measuring vast distances in the universe like the space between stars and galaxies. Judd Bowman of Arizona State University shared the odd findings with Rennan Barkana, of Tel Aviv University in Israel.

Their findings, which were published in the journal Nature, were the result of 12 years of work.

"It is hard to find mechanisms that could increase the radio background at this age in the universe, whereas an explanation for how the gas might be cooler than expected was more assessable", he said. Both would be "very unusual and unexpected", he says. Barkana said it's possible that something could be unusual about the radio background rather than the gas.

"It is possible, for example, that some fraction of the dark matter has a slight electric charge, so small that we would never detect it in environments other than the cosmic dawn", Loeb, who wasn't associated with the study, added.

Shortly after the universe was born, it was plunged into darkness.

Dark matter is matter's mysterious and invisible cousin.

If it is confirmed then this will open the door to a new window on the early universe and potentially a new understanding of the nature of dark matter by providing a new observational window in to it.

The findings have to be confirmed by other experiments.

A U.S. team has captured the faintest of signals from the moment the earliest stars. That something could well be dark matter, the team argues.

Bowman and other astronomers have plans to try to replicate these results using larger radio telescopes in South Africa, hopefully getting even clearer signals from these ancient hydrogen atoms.

"This research is exciting today because it's a very early marker in the evolution of the universe", Rogers said.

We now think that dark matter has to be made of a new kind of fundamental particle.