The White Dots in This Image Are Not Stars or Galaxies. They're Black Holes

MICHELLE STARR 22 FEBRUARY 2021

The image above may look like a fairly normal picture of the night sky, but what you're looking at is a lot more special than just glittering stars. Each of those white dots is an active supermassive black hole.

And each of those black holes is devouring material at the heart of a galaxy millions of light-years away - that's how they could be pinpointed at all.

Totalling 25,000 such dots, astronomers have created the most detailed map to date of black holes at low radio frequencies, an achievement that took years and a Europe-sized radio telescope to compile.

"This is the result of many years of work on incredibly difficult data," explained astronomer Francesco de Gasperin of the University of Hamburg in Germany. "We had to invent new methods to convert the radio signals into images of the sky."



More:
https://www.sciencealert.com/every-white-dot-in-this-image-is-a-black-hole-at-the-heart-of-a-distant-galaxy