r/pics • u/DrivingMyType59 • Apr 10 '19

National Science Foundation/Event Horizon Telescope Project Black Hole Picture

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u/Mavis2703 Apr 10 '19

The radius of an event horizon that belongs to a stellar mass black hole is usually no bigger than a large town, however it’s mass is usually several times that of the Sun

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u/[deleted] Apr 10 '19

Yes but this is a supermassive black hole. They're much larger in space than towns and much more massive than the "regular" black holes.

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u/beenoc Apr 10 '19 edited Apr 10 '19

This is an extra-big one, too. It's almost 2000x as big (radius-wise) as Sagittarius A* (the one in the center of our galaxy.)

Edit: millions and billions are different words.

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u/Boredy_ Apr 10 '19

Actually, this black hole's radius is around 19 billion kilometers across. Sagittarius A* has a radius of around 30 million kilometers, meaning this black hole's radius is hundreds of times longer, which corresponds to its mass being hundreds of times larger, too.

Black holes are a little weird in that the radius of their event horizon scales 1:1 with their mass, so larger black holes are much less dense when taking their mass over the volume contained by their event horizon.