Here's a short (12 page) and pretty easy article from The Astrophysical Journal (2003), about end of life for massive stars. And why some would "directly" collapse (no big & bright supernova) into black holes.
It's been a while since I crawled Wikipedia's rabbit hole on this - but I recall there being regions of the stellar "mass vs. metallicity" graph in which direct collapse to a black hole is the expected outcome.
not an astro anything, but the easy question is how does the sun switch off it's light output so suddenly as to cause a perfect garavitational collapse
presumably it has to be a large metal rich star and exist without too much local gas or a companion star
one thing is clear at this point is that the variety of stelar and galactic variability is much larger than what was predicted even a few decades ago, though the idea of a star just neatly removing itself from this universe when it's done, is very strange indeed
Depends how you define the boundry of the event itself, both in space and in time.
Stellar cores are relatively small, and the infalling matter is essentially in freefall at high g, gets to a significant fraction of c in about 0.1 seconds.
The visible disk of a red supergiant — of the kind that can supernova or surprise us by failing — is on the order of multiple AU radius, so speed of light limits there are in the tens of minutes.
You basically let material stream into a black hole, it forms an acreation disk which gets very hot and dense even before the material actually falls into the black hole. The temperatture and pressure is high enough to trigger nucleosynthetic fusion reactions that generate heavy elements from lighter stuff, like the abundant hydrogen and helium. And a lot of "process heat" that can be used as energy source for other purposes. :)
Perhaps a superadvanced civilization training an AI model on all remaining negative entropy in their solar system so they can more effectively create realistic propaganda for the upcoming election on their now rather chilly mars colony.
They could have used a dense Dyson sphere to “suck” the energy of the star, but if that was the case we would be able to detect its infrared radiation.
https://en.wikipedia.org/wiki/Dyson_sphere
Anyway, I prefer the giant star eating dragon alternative ;-)
Like people spent years of their life scientifically studying the problem and didn’t think of this before making the claim?
It was multi-wave analysis not just visible light, IR spread can differentiate this.
It’s been missing since 2015. Probability of something being large enough to cover the star and stay on a path completely obscuring it for 10 years is shall we say, not likely.
It didn’t rage against the dying of the light, it just switched off.
bell-cot|10 months ago
https://open.clemson.edu/cgi/viewcontent.cgi?article=1006&co...
andrewstuart|10 months ago
Imagine seeing that up fairly close - a massive star just shrivel into a black hole and wink out.
pavel_lishin|10 months ago
bell-cot|10 months ago
Is there an astrophysicist in the house?
magicalhippo|10 months ago
But yeah, just a layman so hopefully someone knowledgeable chimes in.
[1]: https://doi.org/10.1093/mnras/staa863
[2]: https://doi.org/10.3847/1538-4357/acda94
[3]: https://arxiv.org/abs/2503.23856
metalman|10 months ago
amelius|10 months ago
ben_w|10 months ago
Stellar cores are relatively small, and the infalling matter is essentially in freefall at high g, gets to a significant fraction of c in about 0.1 seconds.
The visible disk of a red supergiant — of the kind that can supernova or surprise us by failing — is on the order of multiple AU radius, so speed of light limits there are in the tens of minutes.
mikhailfranco|10 months ago
Is that a significant contribution to 'dark matter'?
unknown|10 months ago
[deleted]
therealfiona|10 months ago
https://arxiv.org/abs/2309.16121
udev4096|10 months ago
verbify|10 months ago
roman_soldier|10 months ago
m4rtink|10 months ago
Orions Arm even has a story about how such process might look like: https://www.orionsarm.com/eg-article/46709da5de6be
You basically let material stream into a black hole, it forms an acreation disk which gets very hot and dense even before the material actually falls into the black hole. The temperatture and pressure is high enough to trigger nucleosynthetic fusion reactions that generate heavy elements from lighter stuff, like the abundant hydrogen and helium. And a lot of "process heat" that can be used as energy source for other purposes. :)
adonovan|10 months ago
NKosmatos|10 months ago
Joking aside, it could be a Kardashev Type II (or higher) civilization. https://en.wikipedia.org/wiki/Kardashev_scale
They could have used a dense Dyson sphere to “suck” the energy of the star, but if that was the case we would be able to detect its infrared radiation. https://en.wikipedia.org/wiki/Dyson_sphere
Anyway, I prefer the giant star eating dragon alternative ;-)
chgs|10 months ago
unknown|10 months ago
[deleted]
unknown|10 months ago
[deleted]
keepamovin|10 months ago
WhitneyLand|10 months ago
It was multi-wave analysis not just visible light, IR spread can differentiate this.
It’s been missing since 2015. Probability of something being large enough to cover the star and stay on a path completely obscuring it for 10 years is shall we say, not likely.
It didn’t rage against the dying of the light, it just switched off.
y42|10 months ago
gpvos|10 months ago