Antimatter Supernova! The Largest Explosion Ever Recorded

We've recently seen the largest explosion ever recorded: a supergiant star two hundred times bigger than the sun utterly obliterated by runaway thermonuclear reactions triggered by gamma ray-driven antimatter production.  The resulting blast was visible for months because it unleashed a  cloud of radioactive material over fifty times the size of our own star, giving off a nuclear fission glow visible from galaxies away.

The super-supernova SN2007bi is an example of a "pair-instability" breakdown, and that's like calling an atomic bomb a "plutonium-pressing" device.  At sizes of around four megayottagrams (that's thirty-two zeros) giant stars are supported against gravitational collapse by gamma ray pressure.  The hotter the core, the higher the energy of these gamma rays - but if they get too energetic, these gamma rays can begin pair production: creating an electron-positron matter-antimatter pair out of pure energy as they pass an atom.  Yes, this does mean that the entire stellar core acts as a gigantic particle accelerator. 

The antimatter annihilates with its opposite, as antimatter is wont to do, but the problem is that the speed of antimatter explosion - which is pretty damn fast - is still a critical delay in the gamma-pressure holding up the star. The outer layers sag in, compressing the core more, raising the temperature, making more energetic gamma rays even more likely to make antimatter and suddenly the whole star is a runaway nuclear reactor beyond the scale of the imagination.  The entire thermonuclear core detonates at once, an atomic warhead that's not just bigger than the Sun - it's bigger than the Sun plus the mass of another ten close by stars. 

The entire star explodes.  No neutron star, no black hole, nothing left behind but an expanding cloud of newly radioactive material and empty space where once was the most massive item you can actually have without ripping space.  The explosion alone triggers alchemy on a suprasolar scale, converting stars' worth of matter into new radioactive elements.

And we saw this.  This really happened.  And ninety percent of people will never know, but can tell you all about Tiger Woods' sex life.

Luke McKinney

Supergiant Supernova 

Comments

[Anon]

"And we saw this. This really happened. And ninety percent of people will never know, but can tell you all about Tiger Woods' wife."

Poignant.

[Andrew T]

"At sizes of around four megayottagrams (that's thirty-two zeros) giant stars are supported against gravitational collapse by gamma ray pressure."

There's a reason why we measure interstellar distances in light-years rather than miles. I have no idea how massive 4 megayottagrams is, but if this were expressed in solar masses, the standard unit of mass at that scale, it would be much clearer.

Inputting "4*10^32 grams in solar masses" into Google yields a result of just over 0.2 solar masses...not very big, especially when the star in question is 3 orders of magnitude larger. I guess this nuclear process must be pretty common in stars.

[Scott H]

I'm with Andrew on this one. A solar mass is about 2 x 10^30 kilograms.

"four megayottagrams" is just 4 x 10^29 kilograms... or 20% of a solar mass. That would be a small red star with a bit less than 1% the luminance of our Sun.

A cool story, but the number don't work at all.

I've found in other articles that it should be a mass of about 200 solar masses. That would be a miss by a nice round factor of 1000. It probably should have been "four gigayottagrams"

Still, I agree with Andrew... why not just "200 solar masses".

[ShadowDs]

"Somebody find Michael Bay immediately - he's somehow gotten into God's chair and we have to stop him."

LOL
Classic!
I love it!

[DavidH]

Good god, Luke are you still in highschool?

How do you write for Daily Galaxy?

[Anonymous Coward]

"Somebody find Michael Bay immediately - he's somehow gotten into God's chair and we have to stop him."

Nice joke, but this explosion actually happened eons before Michael Bay was born.

[amateur]

I'm no expert, but is this the type of phenomenon that is the source of gamma bursts? There was a PBS doc on this a couple of years ago, and they said it was like the Sun releasing all its energy in 10 seconds

[Scott G]

Anonymous Coward, you realize that if he's in the God chair, time ceases to be any kind of obstacle right? I mean, if we're talking about ridiculous impossibilities, manipulation of time is pretty low on the list.

But that was pretty fantastic. Good write up.

[Patrick Stoffel]

Actually, probably more like ninety-nine percent...

[Greg Fish]

Luke, are you serious?

Yes, a star over 130 solar masses would produce antimatter from the photons it generates after it contracts as it runs out of fuel but a pair-instability supernova is not an antimatter explosion. It's a runaway thermonuclear reaction in the star's core. Stars functioning as giant particle accelerators? Huh? Solar winds don't travel at relativistic speeds and neither do supernova shockwaves.

Also, as pointed out, you have your numbers off by pretty major magnitudes. Really, an hour or two of reading on what a pair-instability supernova is wouldn't hurt. Not at all.

[The AntiGreg]

Greg; Paragraph 3: "a runaway nuclear reactor"

Really, a minute or two of reading on what [sic] the article you're complaining about says wouldn't hurt. Not at all.

[Greg Fish]

paragraph #3 says: "Paragraph 3: 'a runaway nuclear reactor'..."

Yes, there are two awkward sentences about the balance between gravity and stellar radiation described by the Eddington luminosity limit -- which by the way is never mentioned despite playing a major role here -- between the superlatives and the constant repetition of the word "antimatter." However, the article states that...

"The outer layers sag in, compressing the core more, raising the temperature, making more energetic gamma rays even more likely to make antimatter and suddenly the whole star is a runaway nuclear reactor beyond the scale of the imagination."

No. At this point the core is basically overheated and tears itself apart because it now has more thermal energy than the gravitational binding energy of the star. Hence no black hole or neutron star. The entire system is torn apart by basic physics. Matter/antimatter pair production is the trigger in a chain reaction, but not the cause of the supernova itself. Thus calling it an antimatter supernova is incorrect.

I think the author just kept using the word "antimatter" because he thought it was really cool to use it over and over again.

[Jack]

You commentors have completely ruined the awe that initially came into being by reading this. Well done.

[Pieter]

OK... it's a pretty impressive kaboom to be sure. I'm glad it happened a long way from us. However Tiger Woods is a slut beyond all reason and he was banging away right here on earth. One event is awesome and huge, but the other is just plain unbelievable...
Is the author going to give us some more Tiger Woods gossip or not? And if not - why not?

[Heinrich D. Bag]

Photoshopped.

[Bart]

Wow, the image looks just like a magnified lens flare, how impressive. Furthermore, antimatter may sounds cool and all, but why waste time on explaining some solar event happening unimaginably far away from us? If one of the stars in a more dangerous proximity to Terra would do something like that, I'd be worried and impressed more.

[Joe Dirt]

Typo FTL.

[mitch]

I completely agree with your last comment.

[Lance Calkins]

It is important to be able to tell facts from opinion. Fact: very large star exploded like a bomb. Opinion: how it happened. Now I just have more questions. It seems every time I learn something I then have 5 more questions. So the more I learn the more I realize I don't know that much. Q1: How do gamma rays turn back into matter and antimatter to then have a reaction? Q2: If antimatter and nuclear reactions both emit gamma rays then how do you know which type of reaction happened? Q3:How were the positrons made? Q4: If nuclear reactions and antimatter reactions produce the same amount of energy then how do you tell the difference and does it matter? Q5: Is any of this useful information for the physics of a reactor on earth?

[Mat]

When was the last time a supernova was visible with the naked eye from the earth? I heard about one being visible in China in the year 500 or so.

[therealdeal]

http://en.wikipedia.org/wiki/Pair-instability_supernova

[daniel mcclain]

I agree with the last statement. I can't believe how many people know all of the celebrity gossip, but when it comes down to the actual important things in life they know absolutly nothing. Amazing story.

[Steve]

Chuck norris farted, that's what happened.

[Urban Prophet]

Someone just posted that Obama was the best president ever....this is the aftermath.

[man]

Its o.k but when did this happen? say some billions of years back!!
can some one shed light on this! Anti-matter, is it visible to the naked eye?