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Astronomers have been mind-boggled to discover what appear to be mega-galaxies dating back to within 600 million years of the beginning of the universe.
Labelled by one scientist as universe breakers, each of the six objects are likely to weigh billions of times more than the sun.
These discoveries are among the first data sets to have come through the James Webb telescope, which was launched in December 2021.
Joel Leja is an astrophysicist who took part in the study.
He spoke to Kim Hill.