How do Planck stars form?

These stars form in a similar way to black holes, but with some crucial differences

1 A star is born

A massive star is born in a cloud of dust and gas: a nebula. If the star is at least 10 to 20 times the mass of the Sun, it will have the chance of forming a black hole.

4 Planck star

This dense core collapses further until it reaches the smallest length possible – the Planck length, a trillionth of a trillionth of a metre in size – forming a Planck star.

6 Stuck in slow motion

The event horizon is actually collapsing towards the Planck star rapidly, but the strong gravity causes time dilation, making the process appear to take billions of years from the outside.

7 Big Bounce

Eventually the infalling event horizon reaches the Planck star, at which point the star rebounds outwards in a new explosion, producing a gamma-ray burst.

2 End of the road

As the giant star reaches the end of its life, it runs out of fuel. When this happens it can no longer support itself under its own gravity, and it collapses.

3 Going supernova

As the star collapses, its infalling material hits its core, and rebounds back into space in a violent explosion known as a supernova, leaving behind a dense core.

5 Event horizon

The Planck star is surrounded by a region known as the event horizon, where nothing – not even light – can escape its pull.

8 Black hole dust

The remnants of the black hole and Planck star are left behind in the form of black hole dust, the signature of which could be detected from afar.