A Star Becomes a Black Hole

A very massive star can run out of fuel and collapse. Its outer layers blast away, and the core can shrink into a tiny, extremely dense black hole.

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In the picture

The massive star: a huge, hot ball of glowing gas.
The collapsing core: a small dense center sinking inward.
The expanding cloud: hot gas thrown outward from the star.
The tiny bright point: an extremely small, dense remnant left by the core.
The dimple around the point: a deep dip in the background.

Examples

A bowling ball on a trampoline makes a dip in the fabric, like the dimple around a black hole.
A snowball squeezed in your hand gets smaller and denser.

Key takeaways

A massive star can leave behind a stellar black hole after a supernova.
A stellar black hole is extremely small and dense, and it warps space around it.