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Comment by the8472 | Hacker News Reader

An interesting tidbit is that the region of stellar parameters where the explosion is so massive that it leaves behind no compact remnant borders directly on the region where stars can collapse into a black hole without a supernova, they just wink out of existence.

https://upload.wikimedia.org/wikipedia/commons/1/18/Remnants...

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So that chart seems to imply it is unknown whether the Sun will end up with "electron capture collapse" or as a neutron star. That's news to me, because when I was younger, I had the impression that the accepted theory was it would become a white dwarf.

I think you're reading the exponent wrong. 10 times the mass of the sun where we generally get a neutron star; 9 times the mass of the sun is too light, so we get electron capture collapses; lighter still, and down to one times the mass of the sun (10^0 solar masses, the origin of the log-scale x axis) is where we get white dwarfs.

Yeah, thanks, I seem to have forgotten the difference between 10^0 and 10^1.

Even the direct black holes dont quietly wink out. Once an even horizon forms, anything outside in now in a forming accretion disk. As things contract they start spinning. Things get hot/loud/bright until that disk settles dow.

Am I reading wrong, or is no remnant in the middle of a black hole formation region?

It looks like “direct black hole” is on both sides of “no remnants”.

I guess on both sides they start out as star -> collapse, but one either side the collapse continues into a hole. Within those parameters the star will stop collapsing and go supernova and never collapse back. I guess that's what it means.

Yes, this most likely just means that different processes are responsible for the same outcome (i.e. becoming a blackhole), depending on the mass of the star.

Edit: see https://en.wikipedia.org/wiki/Pair-instability_supernova#250...

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