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A star appears to have collapsed straight into a black hole without supernova (2017)

science.nasa.gov

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Re: A star appears to have collapsed straight into a black hole without supernova (2017)

#11

Post by MoonGhost »

madaxe_again wrote: post #8
metalman wrote: post #6

Earlier quoted context omitted.

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 i…

It doesn’t necessarily switch anything off or collapse - it’s possible for a star of the right mass and density to simply end up with a core that is held up only by degeneracy pressure, and the core slowly shrinks as it cools until it lies within its schwarzschild radius, and the rest of the star is either quietly consumed by this relatively slow process, or just escapes as though nothing much happened. Which from th…

It cannot just escape without a push as the gravity is still the same?

Re: A star appears to have collapsed straight into a black hole without supernova (2017)

#12

Post by ben_w »

amelius wrote: post #9

What is the timespan of such an event?

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.

Re: A star appears to have collapsed straight into a black hole without supernova (2017)

#13

Post by y42 »

keepamovin wrote: post #7

Or something just moved in front of it. It did not rage against the dying of the light, the definition of out with a whimper.

>As many as 30 percent of such stars, it seems, may quietly collapse into black holes — no supernova required.

Re: A star appears to have collapsed straight into a black hole without supernova (2017)

#17

Post by m4rtink »

roman_soldier wrote: post #5

Could be an advanced civilisation sucking all the stars energy into the back of their spaceship.

More likely just someone feeding all the mass of the star to a black hole for industrial purposes - eq. a Deep Well Industrial Zone: https://www.orionsarm.com/eg-article/464790d2497de

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. :)

Re: A star appears to have collapsed straight into a black hole without supernova (2017)

#18

Post by bell-cot »

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.

https://open.clemson.edu/cgi/viewcontent.cgi?article=1006&co...

Re: A star appears to have collapsed straight into a black hole without supernova (2017)

#19

Post by WhitneyLand »

keepamovin wrote: post #7

Or something just moved in front of it. It did not rage against the dying of the light, the definition of out with a whimper.

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.

Re: A star appears to have collapsed straight into a black hole without supernova (2017)

#20

Post by magicalhippo »

bell-cot wrote: post #3

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. Is there an astrophysicist in the house?

Seems this is the case for both supermassive black hole formation[1][2], and stellar direct-collapse black holes due to failed supernova[3].

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

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