A giant star may have destroyed itself in one of the rarest explosions | Hacker News Reader

A giant star may have destroyed itself in one of the rarest explosions

phys.org

215 pointswglb40 comments

There 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

My favourite kind of supernova, due to their absurdity.

A 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

The 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.

It'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.

Lay article on this supernova https://phys.org/news/2026-05-giant-star-destroyed-universe-...

I don't know much about those things, but if we're seen it now it's because it happens thousands of years ago, right?

1.3 billion actually.

This one was 1.3 billion light years away. Technically that is thousands of years ago. 1,300,000 thousands, approximately.

It'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)

I 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://en.wikipedia.org/wiki/Nancy_Grace_Roman_Space_Telesc...

Well I mean I would expect that the gold would be fired off in all directions as more of an atomic mist than a chunk

Check 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...

Wow, 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

the 100 meter "starshade" probably has much higher chance to be built/launched next decade

it will block overwhelming starlight physically so objects around them can be imaged by existing telescopes

rather simple/clever, some things you just cannot do digitally

* https://www.nature.com/articles/s41550-026-02787-9

* https://www.youtube.com/watch?v=zdTsaf68wd8

He has stopped Mtf trans females from competing in female sports thus pretty much segregating 10s of millions of Americans and people of color.

I don't think it's possible to do worse, even for him.

Response to supposed facts: "Carefully, he's a hero"

Arxiv reprint: https://arxiv.org/abs/2605.16487

Thanks! We've added it to the thread header.

may have. Or not.

Dark Forest theory, anyone?

It was a supergiant, hence died at a young age, and unlikely to have evolved life of any kind in its system.

That’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)

  > before they send a Photoid

Plenty of services require a Photo ID nowadays.

Pair-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.

I 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?

Doesn't that validate the dark forest theory?

A more powerful hidden intelligent system will probably fear a medium power intelligent civlization that sets out to destroy "newcomers" as a civilization that might cause their destruction so the best course of action would be to destroy the medium power one before they become as powerful.

Once multiple destructions have occured, every sentient party capable of becoming aware will fear the others.

Once a civilization reaches a certain tech level, it can do interstellar travel & by the time you find about it due to light speed delay, it might be far too late to strike - not to mention what size & tech level they might be by the point your first strike wave arrives given the time scales of sub light travel.

So it might be better to use the tried and tested terrestrial nuclear MAD doctrine & rather doe careful diplomacy with any newcomers, like a bunch of psychos each having a full arsenal of planet killing weapons (because that's what any sufficiently advanced civilization is).

In short - rather than Dark Forrest I imagine a harmonious if not utopic galaxy teaming with varied life that is on the first glance peaceful and cooperating.

With the occasional bunch of start systems evaporating once in a while, but we don't talk about those.

Spontaneous combustion[1] at scale

[1] https://en.wikipedia.org/wiki/Spontaneous_combustion

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