Break out the record books, because we’ve just found the most distant galaxy we’ve ever seen. Discovered by the Hubble Space Telescope, it lets us peer back into the far reaches of the universe.
Called GN-z11, the galaxy is seen as it appeared 13.4 billion years ago, and owing to the expansion of the universe it is now more than 32 billion light-years from Earth. This means we are looking at it just 400 million years after the Big Bang, which is seriously impressive. The previous record for the most distant galaxy we’d found, EGS8p7, came in at 13.2 billion years.
The discovery of GN-z11 will be published in The Astrophysical Journal on March 8.
"We've taken a major step back in time, beyond what we'd ever expected to be able to do with Hubble,” said principal investigator Pascal Oesch of Yale University in New Haven, Connecticut in a statement. “We see GN-z11 at a time when the universe was only three percent of its current age."
NASA and ESA's Hubble Space Telescope was launched in April 1990. NASA
The galaxy, found in the Ursa Major constellation, is especially interesting because astronomers had not expected to find something so distant in Hubble images. It was only made possible by the high rate of star formation for the galaxy. This makes it rather bright, and allowed Hubble’s Wide Field Camera 3 to measure the “redshift” of the galaxy. The greater the redshift, the farther the galaxy. This galaxy’s light was redshifted by a factor of 11.1, compared to 8.63 for the previous record holder.
GN-z11 is 25 times smaller than the Milky Way and has just one percent of the mass of stars our galaxy has. But it is forming stars at a rate 20 times faster than the Milky Way, which astronomers said was surprising for a galaxy that formed so soon after the Big Bang,
“It’s amazing that a galaxy so massive existed only 200 to 300 million years after the very first stars started to form,” study coauthor Garth Illingworth of the University of California-Santa Cruz said in the statement.
A close-up of the galaxy. NASA / ESA / P. Oesch / G. Brammer / P. van Dokkum / G. Illingworth
As mentioned, this galaxy is pushing the limits of Hubble, and it is unlikely it will ever find a galaxy at an even further distance. But astronomers are expecting that, with the launch of the James Webb Space Telescope (JWST) in 2018, they will be able to peer even further back into the history of the universe.
"This new discovery shows that the Webb telescope will surely find many such young galaxies reaching back to when the first galaxies were forming," added Illingworth.