Last Updated on May 24, 2026 by Staff
At the center of big galaxies there is a supermassive black hole. This thing is so dense that not even light can get away from it. When these black holes eat gas and other stuff around them they become really bright and are called quasars. Some quasars are hidden behind big clouds of cosmic dust, which makes it hard for astronomers to find them.
Now scientists have found 77 quasars that are covered in dust. These quasars are special because they might be a part of how galaxies grow. The scientists wrote about their discovery in a study that they put on the internet.
Hidden Black Holes
Astronomers think that galaxies change when they crash into each other. When this happens a lot of gas goes to the center of the galaxy which makes a lot of stars and feeds the supermassive black hole. During this time the black hole is covered in dust so we cannot see it with telescopes.
These quasars are called reddened quasars because the dust makes the light coming from them look red. Scientists think these hidden quasars are a step in the growth of galaxies and black holes.
Before scientists only knew about 50 of these hidden quasars. They had to look at each one which took a long time.
A New Search
The new study, led by astronomer Matthew Stepney found a lot more of these hidden quasars. They used a telescope called SPHEREx to look at the whole sky and find these quasars. They found 77 ones that we did not know about before.
These quasars are really old. They existed when the universe was between 1.6 billion and 4.3 billion years old. Some of them are even older from when the universe was really young.
Between Two Extremes
Scientists compared these quasars to two other types of objects. One type is called Dust-Obscured Galaxies, which have black holes covered in hot dust. The other type is quasars that we can see clearly.
The hidden quasars are in between these two types. But scientists found that these quasars do not have as much hot dust as regular quasars.
The Blow-Out Phase
Scientists found that these hidden quasars are really bright even though they are covered in dust. They think that these quasars are in a phase where they are blowing away the dust and gas around them. This process will eventually make them visible.
Scientists think this blow-out phase is important for the growth of galaxies. It can help control how many stars are made and what the galaxy will look like in the future.
Cosmic Mysteries Ahead
Scientists also found something: a lot of these quasars have extra ultraviolet light. They are not sure where this light comes from. They think it might be from the quasar itself or from new stars being made.
This discovery is exciting because it can help us learn more about how supermassive black holes grew in the universe. Scientists want to keep looking for hidden quasars to understand how they affected the growth of galaxies.
The universe still has secrets and scientists think that many powerful black holes might still be hidden behind dust waiting to be found..