But this bright blue star has long since disappeared, so massive that it almost certainly exploded into pieces just millions of years after its emergence. His rapid demise makes it even more incredible that an international team spotted him with observations from the Hubble Space Telescope. It takes centuries for light emitted by distant stars to reach us.
“We see the star as it was about 12.8 billion years ago, which puts it about 900 million years after the Big Bang,” said astronomer Brian Wells, a doctoral student at Johns Hopkins University and lead author of the study. Nature on Wednesday.
“We were definitely lucky.”
He named it Earendel, an Old English name meaning morning star or rising light – “an apt name for a star we have observed at a time often referred to as ‘Cosmic Dawn’”.
This shows Earendel’s position along a ripple in space-time (dashed line) that magnifies it and makes it possible to locate the star at such a great distance – almost 13 billion light-years. A cluster of stars is reflected on both sides of the magnifying glass. The deformation is the result of the mass of a huge cluster of galaxies. (NASA, ESA, Brian Welch [JHU]Dan Coe [STScI]; Image processing: NASA, ESA, Alyssa Pagan [STScI])
The previous record holder, Icarus, also a blue supergiant star spotted by Hubble, formed 9.4 billion years ago. This is more than four billion years after the Big Bang.
In both cases, astronomers used a technique known as gravitational lensing to magnify tiny starlight. Gravity from the clusters of galaxies closest to us – in the foreground – serves as a lens for magnifying smaller objects in the background. If this were not the case, Icarus and Arendel would not be distinguished by their enormous distances.
“A gift… from the universe”
While Hubble has been spying on galaxies 300 to 400 million years after the Big Bang formed by the universe, their individual stars are indistinguishable. “Usually they all squeeze together … But here, nature has given us this one star – it is very, very large, it is magnified by thousands of factors – so we can study it,” said NASA astrophysicist Jane Rigby, who took part of the study. “It’s such a gift really from the universe.” Vinicius Placco of NOIRLab at the National Science Foundation in Tucson, Arizona, described the findings as “amazing work.” He did not participate in the study. Placco said based on Hubble data, Earendel may well have been among the first generation of stars to be born after the Big Bang. Future observations from the recently launched James Webb Space Telescope should provide more detail, he said, and “give us another piece of this cosmic puzzle that is the evolution of our universe.” CLOCKS Record-breaking: Hubble spotted farthest star ever: Current data indicate that Earendel was more than 50 times the size of our sun and is estimated to have been a million times brighter, surpassing Icarus. Earedel’s small, yet mature home galaxy bore no resemblance to the beautiful spiral galaxies photographed elsewhere by Hubble, according to Welch, but rather “a kind of awkward-looking, lean object.” Unlike Arendel, he said, this galaxy has probably survived, albeit in a different form after merging with other galaxies. “It’s like a small snapshot of the amber of the past,” Rigby said. Arendel may have been the leading star in a two-star or binary star system, or even a triple or quadruple star system, Weltz said. There is a small chance it could be a black hole, although observations collected in 2016 and 2019 suggest otherwise, he noted. Regardless of his company, the star lasted only a few million years before exploding as an unnoticed supernova, as most do, Welch said. The most distant supernova ever seen by astronomers dates back 12 billion years. The Webb telescope – 100 times more powerful than the Hubble – should help clarify how huge and hot the star really is and reveal more about its parent galaxy. Studying the stars, Rigby said: “We literally understand where we come from because we are made up of a little bit of this stardust.”
