It’s been weeks since JWST startedtraveling into the past by taking pH๏τos of galaxies 13 billion years old ormore. The telescope (JWST) has broken the record for discovering the oldestgalaxy so far about almost 100 million years after the big bang.

GN-z11, the previous candidate for the mostdistant galaxy discovered, appears as the red object in the center of thezoom-in image. Harikane et al. One of the key goals of JWST is to see veryfirst galaxies formed just after the big bang 13.8 billion years ago. Thecurrent oldest galaxy – called GN-z11 found by the Hubble ST formedabout 400 million years after the birth of the universe.

Astrophysicist Rohan Naidu from Harvard and histeam of workers from Smithsonian Centre of Astrophysics in Mᴀssachusetts believethey’ve found the oldest galaxy in a dataset of JWST which was publiclyreleased few weeks back – called GLᴀss. The Galaxy’s name is GLᴀss-z13, thisgalaxy formed about 300 million years after the big bang. Rohan’s team also founda second galaxy, at a same age to GN-z11.

“We found two very compellingcandidates for extremely distant galaxies,” says Naidu. “If these galaxies areat the distance we think they are, the universe is only a few hundred millionyears old at that point.”

GLᴀss-z13 is the oldest galaxy ever seenNaidu et al, P. Oesch, T. Treu, GLᴀss-JWST, NASA/CSA/ESA/STScI

These two galaxies have equivalent mᴀss ofabout a billion suns in this time. That is very unique feature only thought tohave in galaxies upto 500 million years old, concludes the team, this might bea hint that the stars usually formed more rapidly than we believed in the earlyuniverse. The galaxy which is close to big bang , Glᴀss-z11, also started todevelop disc-like structure due to its rotation.

These new two galaxies are very small ascompared to our Milky Way galaxy. (GLᴀss z-13 is only 1600 light years acrossand z-11 is 2300 light years in comparison to Milky Way, Milky Way is some100,000 light years across.) Astrophysicists from Niehls Bohr Insтιтute inDenmark, Gabriel Brammer, was also part of  the GLᴀss teamand helped his team in discovering GN-z11, explained that further study andanalysis is needed to get to exact  the distance between these twogalaxies. 

Only James Webb ST can achieve that.

“They’re very convincingcandidates,” he says. “We were pretty confident that JWST would see distantgalaxies. But we’re a little bit surprised how easy it is to detect them.”

JWST is very very strong and it shouldeasily make discoveries like this on regular basis. It will find galaxies lotmore closer to the Big bang than these two galaxies, maybe 200 million yearsafter the big bang, when the very first galaxies and stars have believed toform.

“How early does star formationstart in the universe?” says Naidu. “It’s one of the last major unknowns in ourbroad timeline of the universe.”

Reference: arxiv.org/abs/2207.09434