A red spot in the background of an image taken by NASA's James Webb Space Telescope (JWST) has been officially recognised as one of the oldest galaxies known to exist in the Universe. The galaxy was named Maisie and spectroscopic analysis confirmed that JWST saw it exactly as it appeared only 390 million years after the Big Bang.

The observations are described in an article in the journal Nature. The researchers found that the galaxy was not as early as it was thought, but this did not prevent it from becoming a record holder.

The scientists, who were part of the team of astronomer Pablo Arrabal Haro from the NOIRLab laboratory of the US National Science Foundation, noted that the results of their study confirmed that the early Universe was much more populated than previously thought.

"The most interesting thing about the Maisie galaxy is that it was one of the first distant galaxies discovered by JWST, and it is the first of this set to receive spectroscopic confirmation," explained Stephen Finkelstein, an astronomer at the University of Texas (USA). It was he who was honoured to name the new galaxy, so he named it after his daughter, whose birthday coincided with the discovery of the galaxy.

Scientists also noted that this study showed that the issue of time should be more carefully studied when analysing JWST observations.

Currently, the redshift is used to determine how distant, and therefore how old, a galaxy or star is. As the Universe expands at an accelerating rate, objects far beyond our galaxy may appear to be moving away. The longer it takes for light from such objects to travel to us, the faster the object appears to be moving away from us.

This "moving away" causes the light wave to stretch, mixing into the red spectrum. It is thanks to this red shift that scientists can determine the distance and age of an object.

As Science Alert explains, JWST studies the Universe in infrared waves, which makes it possible to look into the early Universe much deeper than was previously possible.

When the researchers first published their paper on the Maisie galaxy, they calculated its redshift from the brightness of light passing through several filters. As a result, they found that the galaxy was observed approximately 366 million years after the Big Bang.

Subsequently, in order to prove the correctness of their own calculations, the scientists used the JWST spectroscopic instrument, NIRSpec, which splits light into different wavelengths of the near-infrared range and allows for a more detailed analysis. The NIRSpec data showed a slightly different redshift, indicating that the galaxy appeared about 390 million years after the Big Bang.

Thus, the light from the Maisie Galaxy travelled through space for about 13.4 billion years before it was detected by JWST.

This is how the light travelled through the Universe to the Maisie Galaxy:

Earlier, OBOZREVATEL also reported that a NASA telescope had discovered an intriguing detail about the most distant star in the Universe.

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