The James Webb Space Telescope discovered bright red specks in the early universe, between 600 million and 1.5 billion years after the Big Bang. These specks seemed to disappear in later cosmic history. Astronomers debated their identity for years.
A team led by Pierluigi Rinaldi studied a galaxy nicknamed "Saguaro" because of its shape, similar to a cactus. This galaxy has a bright red center. Researchers simulated how this galaxy would look from very far away. They found that at extreme distances, the galaxy's arms become invisible, leaving only the bright red core visible.
This suggests the red dots are not separate objects but are the supermassive black holes at the centers of galaxies that are too far away to see. The faint outer parts of these galaxies fade into the background.
Data from the James Webb and Hubble telescopes, along with X-ray signals from NASA's Chandra X-ray Observatory, helped build a clearer picture. While many distant red dots don't emit X-rays, possibly due to gas and dust, a newly found object 11.8 billion light-years away does emit them. Scientists think this shows a stage where the gas cloud around the black hole starts to break apart.
Another discovery, MoM-BH*-1, is a "black hole star" about 13 billion light-years away. It's an infant black hole surrounded by a huge gas cloud. This gas creates friction and heat, making it shine very brightly. These findings suggest the red dots are a temporary phase in the development of supermassive black holes within unseen galaxies.