"The researchers discovered HD1 in data collected over 1,200 hours of observation time using the Subaru Telescope, the VISTA Telescope, the U.K. Infrared Telescope and the Spitzer Space Telescope. They were particularly looking at redshift, a phenomenon in which light waves stretch out or become redder as an object moves away from the observer. In this case, the redshift suggested HD1 was extremely distant.

The researchers found that the red wavelengths were the equivalent to a galaxy located 13.5 billion light-years away.

HD1 also seems to be growing at a feverish rate — about 100 stars each year, or at least 10 times the rate predicted for starburst galaxies that are known to produce stars at an extraordinarily high pace.

These stars were also more massive, brighter (in ultraviolet wavelengths) and hotter than younger stars, the researchers found.

As such, HD1 could be home to the universe's very first stars, called Population III stars; if that identity is verified, this would be the first observation of this type of star, the researchers said. There's also the possibility that HD1 is a supermassive black hole with a mass of about 100 million times that of the sun."

Also a paper on it: https://arxiv.org/abs/2201.00823