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LIGO detects most massive black hole merger to date

(www.caltech.edu)
360 points Eduard | 2 comments | 14 Jul 25 20:06 UTC | HN request time: 0.504s | source
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BurningFrog ◴[14 Jul 25 21:40 UTC] No.44565671[source]▶
I've always thought the event horizon for a black hole has to be spherical.

But my physics intuition tells me that as two of them merge, the resulting BH should have a "peanut" shape, at least initially.

And maybe it can keep having an irregular shape, depending on the mass distribution inside it?

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1. chasil ◴[14 Jul 25 21:49 UTC] No.44565738[source]▶
Does the black hole's spin deform the event horizon?

I think so?

https://archive.ph/VrzwW

Edit: "The Kerr metric also predicts the existence of an inner and outer event horizon, with the shape of these horizons being oblate rather than perfectly spherical due to the rotation."

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2. mr_toad ◴[15 Jul 25 12:54 UTC] No.44570643[source]▶
Kind of. Because the black hole drags space around with it you need to go faster near the ‘equator’ than the poles just to stand still. So the event horizon is fatter at the equator.