The James Webb Space Telescope has discovered hundreds of mysterious “little red dots” in the ancient universe, and astronomers are still trying to understand what they are. These small, red, and compact galaxies could either be packed with stars or host enormous black holes, making them unlike anything seen before. Dubbed “Little Red Dots,” these objects are visible during a narrow window of cosmic history, about 1 billion years after the Big Bang. Much like the mimic octopus that impersonates other marine animals, these galaxies appear as different astrophysical objects depending on how they’re studied.
The Little Red Dots are tiny, with a radius only 2% of the Milky Way’s size, and some are even smaller. By examining their light, astronomers aim to determine whether they are densely packed with stars or if they harbor supermassive black holes. The light that telescopes receive is broken into various frequencies and analyzed through a spectrum, which can reveal whether these galaxies contain massive stars or black holes.
Two main hypotheses have emerged: either the Little Red Dots are extremely dense galaxies with up to 100 billion stars, making them some of the most crowded stellar environments in the universe, or they host supermassive black holes that are unexpectedly large for their size. These “overmassive” black holes could provide clues about the early formation of black holes in the universe.
However, these black holes remain elusive, as they lack the expected X-ray emissions even in the deepest observations. This raises questions about their nature and challenges conventional models. Future observations with the Webb telescope and more advanced X-ray telescopes could help unravel the true identity of these enigmatic galaxies, revealing whether they are dominated by stars or by black holes.
Just as the mimic octopus eventually reveals its true form, the Little Red Dots may soon disclose their secrets.