Two of the oldest galaxies ever seen in the universe have been discovered by the James Webb Space Telescope, and they are much brighter than expected, meaning astronomers are rethinking their beliefs about how the first stars formed.
The two galaxies are believed to be billions of years old, just 100 million years after the Big Bang. Digitartlends reported that Webb can look at some of the oldest galaxies because it works in the infrared, which means it can see redshift galaxies.
A redshift occurs when light from a distant galaxy moves to the red end of the spectrum due to the expansion of the universe. Web sees it.
Previous research estimated that some galaxies captured by Webb could have a redshift of up to 14, but the latest results are more accurate thanks to better instrument calibrations and suggest redshifts for two galaxies of 10.5 and 12.5.
Webb also exploits a phenomenon called gravitational lensing, in which a massive object like a galaxy or group of galaxies has so much mass that it warps through space and acts like a magnifying glass, allowing researchers to see more distant galaxies.