Hubble reveals furthest galaxy yet
A team of astronomers has discovered the most distant object in the universe - a galaxy 13 billion light years away.
The galaxy, observed using the Hubble Space Telescope, comes from the relative dawn of the universe a mere 700 million years after the Big Bang.
The discovery is described today in the journal Nature.
Study co-author, Professor Malcolm Bremer, an astrophysicist at the University of Bristol, says the image was made possible by a recent upgrade of the Hubble Space Telescope.
"A short while ago the Hubble Space Telescope was upgraded with a new infrared camera that enabled an image - a very, very deep image - of a small part of the universe to be taken," says Bremer.
"Looking at those images other astronomers identified potential candidates.
"We then took one of the most likely high redshift candidates and actually took spectroscopy of it to show that it was indeed at a very great distance from us. It turns out the most distant object that we've yet confirmed the distance of."
Time of change
According to Bremmer, the discovery of a galaxy 13 billion light years away is important because it formed at a time when the universe was undergoing a significant transition.
"Throughout the universe there is hydrogen gas, it's the most abundant element in the universe," he says.
"After the Big Bang the universe cooled and most of that hydrogen turned neutral. But at some point, at around the distances and the times that we're looking at, the hydrogen gas became ionised.
"What that basically means is it becomes transparent to photons flowing through it.
"We believe we are actually seeing at the time when this critical transition was happening."
Bremmer says, while the galaxy would contain stars, but it is unlikely to contain planets.
"The mix of stars are not necessarily going to be the kind of stars that we see in the Milky Way galaxy, so certainly you wouldn't want to be on a planet anywhere near them," he says.
According to Bremmer, the discovery made the researchers "very excited".
"You can potentially get quite blasé about doing this and then you do stuff and think 'hang on a minute, what have we just done here?'" he says. "This is really, really exciting, this is fantastic."
"It's the first time that man's actually confirmed that they've identified a galaxy that is that far away.
"It is exciting, but you're so sort of close to it that you sometimes have to take a step back and say, 'Wow, we just did that.'"