It’s the first time for astronomers to look at light from the Universe’s first stars. They have glimpsed the dawn of the universe 13.6 billion years ago.
In this time, the earliest stars were just beginning to glow after the Big Bang. Astronomers call this moment the Cosmic Dawn.
Astronomers, through a small antenna, caught a faint radio signal from deep space. The antenna is slightly bigger than a refrigerator and costs less than $5 million. However, it can go back much farther in time and distance than the famous, multibillion-dollar Hubble Space Telescope.
“This is exciting because it is the first look into a particularly important period in the universe when the first stars and galaxies were beginning to form,” said Colin Lonsdale, director of MIT’s Haystack Observatory, in a press release. “This is the first time anybody’s had any direct observational data from the epoch.”
Judd Bowman of Arizona State University is the lead author of a study in Wednesday’s journal Nature. He said the signal came from the very first objects in the universe as it was emerging out of darkness 180 million years after the Big Bang.
Scientists from Arizona State University said in the paper — published in the journal Nature — that the signal also contained evidence of the existence of dark matter, a potential second breakthrough into the history of the universe.
The results of the study revealed that the pre-star universe was likely a much colder place than previously thought. Roughly -454 Fahrenheit. Researchers actually found that the hydrogen gas in the early universe was less than half the temperature they expected to find.
“It’s a time of the universe we really don’t know anything about,” Bowman said. He said the discovery is “like the first sentence” in an early chapter of the history of the cosmos.
How legit is the new discovery?
This is nothing that astronomers could actually see. In fact, it’s all indirect, based on changes in the wavelengths produced by radio signals.
Astronomers looked at a specific wavelength. If there were stars and ultraviolet light, they would see one signature. If there were no stars, they would see another. They saw a clear but faint signal showing there were stars, probably many of them, Bowman said.
“If confirmed, this discovery deserves two Nobel Prizes” for both capturing the signal of the first stars and potential dark matter confirmation, said Harvard astronomer Avi Loeb, who wasn’t part of the research team. Cautioning that “extraordinary claims require extraordinary evidence,” he said researchers need independent tests to verify the findings.
In order to confirm the study’s findings, astronomers intend to bring new radio telescopes online, such as the Hydrogen Epoch of Reionization Array (HERA) and the Owens Valley Long Wavelength Array (OVRO-LWA).
Harvard astronomer Lincoln Greenhill, in an analysis for Nature, mentions that the new discovery might allow astronomers to map the 3D structure of the universe and give new insights into these early dark ages. It might even help researchers finally crack the mystery of what dark matter really is.
So far, the scientists know little about these early stars. They were probably hotter and simpler than modern stars, Ellis and Bowman said. But now that astronomers know where and how to look, others will confirm this and learn more, Bowman said.
Thumbnail image: Artists interpretation of the earliest stars. Credit: NR Fuller/National Science Foundation