Five facts about black holes

Here are five things we know about these unusual objects that play a crucial role in Planck stars

They come in different sizes

Black holes can range in size from microscopic to supermassive black holes, which are billions of times more massive than our Sun and found in the centre of galaxies.

They grew really fast

Black holes in the early universe somehow grew really quickly, reaching supermassive status just a billion years after the Big Bang – but scientists aren’t sure how.

We’ve managed to take an image of one

In April 2019, astronomers from the Event Horizon Telescope (EHT) project revealed they had taken the first image of a black hole, found in the nearby M87 galaxy.

Despite the name, they can be really bright

Some supermassive black holes are surrounded by swirling discs of superheated material, known as a quasar, which can be easily spotted in telescopes, although the black hole remains hidden.

There’s a missing class of black holes

Astronomers believe the universe might be abundant in a medium-sized type of black hole, called an intermediate-mass black hole. However, we’ve struggled to find many of them so far.