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It's generally hard to get stars to collide with black holes since even the very largest black holes are still very small relative to the distances between star
by splat 14y ago
It's generally hard to get stars to collide with black holes since even the very largest black holes are still very small relative to the distances between stars. There's just too much angular momentum that needs to be removed. (Which is not to say that it can't be done -- it can, and there are various mechanisms for doing so, but it's very difficult to do for a substantial fraction of a galaxy's mass.) Even if this occurred, it's nevertheless surprising that it happened in this particular galaxy, and didn't occur in pretty much every other one.
- sambeau 14y agoFascinating. I'm clearly guilty of believing left Black Holes are like plug-holes in the centre of galaxies and eventually everything will swirl down them. So this isn't a valid picture? Do you have a more realistic one for me instead to think about?
- splat 14y agoFar from the event horizon, a black hole acts like a point mass just like every other star. If, for instance, the Sun were to immediately turn into a black hole, the Earth would continue to orbit it as if there had been no change.
- sambeau 14y agoAssuming it kept the same mass? And even if it had a lot more mass?
- splat 14y agoAssuming it kept the same mass. If it had a lot more mass, the Earth's orbit would be identical to it's orbit around a star with that much more mass. The fact that an object is a black hole only becomes relevant when something passes the event horizon. Outside the event horizon, it acts like any other object with the same mass.