James Webb telescope sees most distant galaxy

A LJMU scientist on the James Webb Space Telescope team says the discovery of a record-breaking galaxy is one of the most “stunning” galaxy discoveries for years.

Dr Renske Smit, says this most-distant galaxy ever seen is ultra-bright most likely because it is creating stars in a different way to those formed in the Milky Way.

“This galaxy could be producing very few stars like our own sun, but rather lots of ‘monster’ stars that are dozens if not hundreds of times more massive than our sun! These massive stars shine very brightly, such that we can see them over enormous cosmic distances with telescopes like Webb,” said the scientist from LJMU’s Astrophysics Research Institute.

The galaxy, called JADES-GS-z14-0, is revealed as it was just 290m years after the big bang, at the dawn of the universe. The previous record holder was a galaxy seen at 325m years after the big bang, which happened nearly 14bn years ago.

“The universe at these early stages was different from it is today,” said Dr Francesco D’Eugenio, of the University of Cambridge, one of the team leaders.

“Early galaxies – this is the most distant found, but there are others – seem to be brighter than expected from the models.”

The $10bn James Webb Space Telescope, launched in 2021, can see further across the cosmos than any previous telescope. Due to the expansion of the universe, the light from distant galaxies stretches to longer wavelengths as it travels, an effect known as redshift. In these galaxies the effect is extreme, stretching by a factor of 15, and moving even the ultraviolet light of the galaxies to infrared wavelengths where only the James Webb Space Telescope has the capability to see it.

These incredibly distant observations reveal the universe in its infant state and are already transforming scientists’ understanding of the early universe. An emerging theme is that galaxies and black holes appear to have grown much more rapidly than was expected. 

Added Dr Smit: “This galaxy is not the first to be found to be so bright in the early Universe (or Cosmic Dawn), but it certainly is the most distant.

“In previous discoveries it was suggested that the galaxy might be hosting a supermassive black hole in the process of ‘eating’ large amounts of gas. This process gives off a lot of light, such that the eating black hole outshines the stars in the galaxy. However, for this particularly intriguing galaxy, we see no evidence of that; instead this early galaxy could be so bright because it is forming stars in very different way from how stars are formed in our own Milky Way.”