REBELS-25 is a massive, star-forming rotating disc galaxy[1][2] with a redshift of 7.31.
[3] It was discovered using the Atacama Large Millimeter/submillimeter Array (ALMA),[4][5] notice of its discovery was published in the Monthly Notices of the Royal Astronomical Society.
REBELS-25 existed just 700 million years after the Big Bang.
[6][7] The discovery of such an ancient galaxy not only makes it the oldest known galaxy, but it is another piece of mounting evidence that suggests cosmologists need to revise their previous notions on galactic evolution.
[8] REBELS-25 is very complex compared to what was expected for a galaxy of its age: researchers discovered that it rotates (with the help of blueshift and redshift), and also shows traces of spiral arms as "modern" galaxies, like the Milky Way, has.