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A giant star may have destroyed itself in one of the rarest explosions
https://arxiv.org/abs/2605.16487 https://arxiv.org/abs/2605.16487
- wglb 4mo agoArxiv reprint: https://arxiv.org/abs/2605.16487 https://arxiv.org/abs/2605.16487
- tomhow 4mo agoThanks! We've added it to the thread header.
- chasil 4mo agoThere is a wiki on pair-instability supernovas. Antimatter (in the form of positrons) is a key factor. https://en.wikipedia.org/wiki/Pair-instability_supernova https://en.wikipedia.org/wiki/Pair-instability_supernova
- ben_w 4mo agoMy favourite kind of supernova, due to their absurdity.
- chasil 4mo agoA hypernova is an even larger star that is theorized to end its life due to photodisintegration rather than pair instability. https://en.wikipedia.org/wiki/Photodisintegration#Hypernovae https://en.wikipedia.org/wiki/Photodisintegration#Hypernovae
- pfdietz 4mo agoThe temperature involved for this is well above that needed for production of electron-positron pairs, so one may ask why that doesn't happen. I think it's because the cores of such stars are dense enough the electrons are degenerate, and there simply isn't "room" for new electrons to be added at an energy that would make pair production possible. BTW, I don't think largeness is needed for photodisintegration to occur; this should happen even in garden variety type-II SN.
- pfdietz 4mo agoIt's my understanding the general mechanism of core collapse involves the adiabatic constant of the material, gamma. This is the exponent in the relation P V^(gamma) = constant. For a normal, non-relativistic gas in which the particles have no internal degrees of freedom, gamma is 5/3. As a gas becomes more relativistic, and as photon pressure becomes more important, gamma declines toward 4/3. For gamma = 4/3, a self-gravitating gas will be marginally stable: the energy needed to compress a sphere of the gas will be equal to the gravitational potential energy liberated by the compression. So, any effect that pushes gamma below 4/3 makes it unstable against collapse. In a conventional core collapse SN this is photodissociation of nuclei, where energy gets soaked up in breaking apart nuclei into alpha particles and then free nucleons. In a pair-instability SN, this is increasing conversion of photons to electron-positron pairs.
- bebeidjdkrjrjr 4mo ago[flagged]
- wewtyflakes 4mo agoI know you are a bad-faith bot account, so this is not posed to you. I am wondering why there are so many of these accounts popping up. They seemingly only exist to antagonize. What do their operators get out of that?
- junon 4mo agoWhat do 14 year olds get out of trolling anything? A cheap grin and something to do on an after school evening.
- conception 4mo agoAnd nation state actors actively attempting to disrupt western society.
- junon 4mo agoThey're not doing that from HN by posting edgy comments. We're not a high priority, they target social media with billions of users.
- detritus 4mo agoheh, funny you say that - I just yesterday almost bit at some obvious Nego-Trolling on here and remembered "Just don't engage". Some people, for some reason at certain points in their life, just want to shit on other people's stuff, any way that they can, for... reasons. I mean, clearly it's not to make themselves feel better, because how on Earth could that work? There's no value in engaging, in any way whatsover. Sadly there's very little that can be done to prevent that form of human behaviour, without otherwise souring the experience for the generality. *shrug, whatchagonnado?
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- ck2 4mo agoI just want to live long enough for space telescopes to evolve exponentially to observe kilonovas in the visual spectrum I mean laser interferometers are an amazing advancement but just imagine seeing an earth-sized chunk of gold pop out of a kilonova (probably not my lifetime but eventually a human will see it happen) Thank goodness this administration did not frack with Nancy Grace Roman Telescope, I thought the name alone would make them cancel it or rename it after him, wait maybe I shouldn't even mention that idea... * https://science.nasa.gov/mission/roman-space-telescope/ https://science.nasa.gov/mission/roman-space-telescope/ * https://en.wikipedia.org/wiki/Nancy_Grace_Roman_Space_Telescope https://en.wikipedia.org/wiki/Nancy_Grace_Roman_Space_Telesc...
- vitally3643 4mo agoWell I mean I would expect that the gold would be fired off in all directions as more of an atomic mist than a chunk
- deleted 4mo ago[deleted]
- throwaway-away 4mo agoCheck out the aragoscope [1]. It's not planned, but we would already have the technology as it doesn't rely on fragile and heavy lenses to be sent in orbit. If you look at image 17 you can see that a simulated aragoscope that is in our technical reach could already resolve the Jupiter moons from almost 23 light years away. I hope as well that we will have something comparable while I am still around. [1] https://www.nasa.gov/wp-content/uploads/2017/03/2014_phase_i_webster_cash_the_aragoscope.pdf https://www.nasa.gov/wp-content/uploads/2017/03/2014_phase_i...
- Levitating 4mo agoWow, that would be absolutely amazing. For reference, there are 103 known main sequence stars within 20 light years.[1] [1]: https://en.wikipedia.org/wiki/List_of_nearest_stars https://en.wikipedia.org/wiki/List_of_nearest_stars
- timwis 4mo agoDark Forest theory, anyone?
- groos 4mo agoIt was a supergiant, hence died at a young age, and unlikely to have evolved life of any kind in its system.
- tgrowazay 4mo agoThat’s what Singer’s civilization wants you to think before they send a Photoid or Dual-Vector foil (but later would require a supervisor’s approval which is a PITA)
- dotancohen 4mo ago> before they send a Photoid Plenty of services require a Photo ID nowadays.
- chasil 4mo agoPair-instability can only happen in low-metalicity surroundings. The big bang created hydrogen, helium, and small amounts of lithium. Any higher elements are created by stars, and a significant presence of those "metals" will take a star down a different path than pair-instability. Low-metalicity environments are not likely to be friendly to life.
- veltas 4mo agoI like to think there's a solid argument against dark forest that even if you can destroy other intelligent systems, then hidden intelligent cautious systems may exist and see evidence of what you've done, so there's a potential consequence to destroying every intelligent system you identify. And then also (maybe this is absurd) isn't there something intrinsic in intelligence to want to avoid conflict and desire peace?
- whizzter 4mo ago
- smnplk 4mo ago[flagged]
- hulitu 4mo agomay have. Or not.
- fasteo 4mo agoSpontaneous combustion[1] at scale [1] https://en.wikipedia.org/wiki/Spontaneous_combustion https://en.wikipedia.org/wiki/Spontaneous_combustion
- dominictorresmo 4mo agoI don't know much about those things, but if we're seen it now it's because it happens thousands of years ago, right?
- Stolpe 4mo agoIt's 1.3 billion light years away according to the article, so yeah... 1.3 billion years ago. (plus 3 years since it was observed in 2023)
- conception 4mo ago1.3 billion actually.
- zuminator 4mo agoThis one was 1.3 billion light years away. Technically that is thousands of years ago. 1,300,000 thousands, approximately.
- conception 4mo agoLay article on this supernova https://phys.org/news/2026-05-giant-star-destroyed-universe-rarest.html https://phys.org/news/2026-05-giant-star-destroyed-universe-...