Astronomers say they have found the most distant galaxy in the universe, called EGS-zs8-1, measured at 13.1 billion light-years away.
And because the light has taken that amount of time to reach us, experts are observing it at a time when the universe was just five per cent of its current age.
The discovery offers a rare opportunity to see how galaxies began to take shape when the cosmos was still extremely young.
Although the galaxy had previously been found by Nasa’s Hubble and Spitzer telescope, its distance has only now been confirmed.
This was done using the W. M. Keck Observatory’s 33ft (10 metres) telescope in Hawaii.
According to the international team behind the discovery, led by Yale University and the University of California-Santa Cruz, it is the most distant galaxy ever measured.
This new galaxy takes the title from the previous record-holder, z8_GND_5296, which is marginally closer to Earth.
At 13.1 billion light-years away, we are observing EGS-zs8-1 as it looked just 670 million years after the Big Bang.
In that time, it managed to build ‘more than 15 per cent of the mass of our Milky Way today,’ according to Dr Pascal Oesch, a Yale astronomer and lead author of the study, published in Astrophysical Journal Letters.
Only a handful of galaxies currently have accurate distances measured in this very early universe.
‘Every confirmation adds another piece to the puzzle of how the first generations of galaxies formed in the early universe,’ said Dr Pieter van Dokkum, the Sol Goldman Family Professor of Astronomy and chair of Yale’s Department of Astronomy, who is second author of the study.
‘Only the largest telescopes are powerful enough to reach to these large distances.’
The new observations establish EGS-zs8-1 at a time when the universe was undergoing an important change.
Namely, the hydrogen between galaxies was transitioning from a neutral state to an ionised state.
‘It appears that the young stars in the early galaxies like EGS-zs8-1 were the main drivers for this transition, called reionisation,’ said Dr Rychard Bouwens of the Leiden Observatory, co-author of the study.
Taken together, the new Keck Observatory, Hubble, and Spitzer observations also pose new questions.
They confirm that massive galaxies already existed early in the history of the universe, but they also show that those galaxies had very different physical properties from what is seen around us today.
Astronomers now have strong evidence that the peculiar colours of early galaxies – seen in the Spitzer images – originate from a rapid formation of massive, young stars, which interacted with the primordial gas in these galaxies.
It’s unlikely this galaxy will hold onto its title of the ‘most distant’ for too long, though; Nasa’s James Webb Space Telescope (JWST), due to launch in 2018, will be able to peer further back in the history of the universe than any telescope before it.
In addition to pushing the cosmic frontier to even earlier times, the telescope will be able to dissect the light of EGS-zs8-1 seen with the Spitzer telescope and provide astronomers with more detailed insights into its gas properties.
‘Our current observations indicate that it will be very easy to measure accurate distances to these distant galaxies in the future with the James Webb Space Telescope,’ said co-author Dr Garth Illingworth of the University of California-Santa Cruz.
‘The result of JWST’s upcoming measurements will provide a much more complete picture of the formation of galaxies at the cosmic dawn.’