If you followed me Captain America himselfYou’ve probably come across a story about the James Webb Space Telescope’s latest find: the “oldest galaxy we’ve ever seen.”or maybe,
This is exactly what the James Webb Space Telescope promised us. Just a week ago, the global collective jaw dropped when. Now the telescope really gets going but researchers already had access to a wealth of data collected during the commissioning phase of JWST and shared early with researchers around the world.
That’s how we found “the oldest galaxy” so quickly. Scientists trawled through a particular data set looking for distant galaxies and found one candidate They have christened GL-z13, a call back to the currently confirmed record holder GNz11.
More work needs to be done to confirm that GL-z13 is indeed the new record holder – some of which will take more time to point Webb at the galaxy – but nonetheless, multiple releases have already crowned this galaxy the universal champion.
So how did we get here? And is this “the oldest galaxy” ever seen?
In the last 24 hours, two different research groups have uploaded papers (one here, the other here) to arXiv detailing their search for very distant galaxies in the James Webb data.
The website “arXiv” (I pronounce it “ark-siv” because I’m a pagan, but others assure me it’s pronounced “archive”) is a preprint repository, a place for scientists to publish studies, so that they can be quickly passed on to colleagues. It’s a great place to quickly get new research out into the world, especially in astronomy and astrophysics, with the caveat that the results have not usually been peer-reviewed – an important checkpoint for validating the study and its methods.
Hubble and James Webb Space Telescope images compared: see the difference
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I don’t want to poop the party for GL-z13, but I just want to exercise a little caution. When the results are communicated with such certainty, there is a risk that readers will lose faith in the scientists if GL-z13 turns out to be something else entirely. Several astronomers I’ve spoken to believe the data is pretty convincing and the galaxy is probably very far (loooong) away, but until there’s confirmation, GL-z13 can’t hold the title of “oldest galaxy.”
And for some, even that title itself is a bit misleading.
You see, GL-Z13 isn’t really “the oldest galaxy ever” – it dates from a time when the Universe was barely 330 million years old. The light of this galaxy? Well, yeah, it’s super old. It has come a long way to reach the JWST. But the galaxy itself, if confirmed, likely is youngest galaxy ever seen, says Nick Seymour, an astrophysicist at Curtin University in Western Australia.
“330 million years after the Big Bang, it can’t be older than 100 million years at best,” Seymour said. “So this really is a baby galaxy at the dawn of time.”
Enthusiasm for record-breaking space achievements is a given. As a science journalist, I do this almost every day. But when reporting new discoveries, it’s important to convey uncertainty. In headlines, in social posts, in the way we discuss scientific advances. We have to set the right standards and leave this uncertainty. The story of GL-z13 is wonderful and it is just beginning. Astronomers now have to study it a lot more to make sure the distances are correct.
“There’s still a lot of follow-up work to do, of course, but it’s really kind of a taste of where things are going with James Webb,” said Michael Brown, an astrophysicist at Monash University.
That was just in April, before Webb scoured the cosmos. This galaxy is believed to be from a time when the Universe was about 330 million years old. Brown noted at the time that it’s worth taking the title to HD1 with caution, as the data could point to a galaxy billions of light-years closer to Earth. As with GL-z13, we need further observations to confirm its removal.
Do you know which telescope can do that? You guessed it: JWST.
We’re fascinated by records being broken, but perhaps the most interesting point about all of this is that when Webb performs as well as expected (and) the title for the “Oldest Galaxy” will change hands as often as WWE’s 24/7 Hardcore Championship. We will find new galaxies from even further back in time at a rate we could not have dreamed of.
If that’s the case, it won’t be long before the record falls.
Updated July 22nd: Headline changed, added context to oldest galaxy paragraph.