MY EYES! Earth engulfed by BRIGHTEST EVER killer gamma-ray burst Earth has been bathed in its largest recorded burst of gamma rays after a star in the constellation Leo, 3.7 billion light-years away, collapsed in on itself to form a black hole. Youtube Video "This burst was a once in a century cosmic event," said Paul Hertz, director of NASA Astrophysics Division at a press conference on …
The GRB 130472A event wasn't so bright because it was especially large, in universal terms, but because it was so close to Earth and our planet was in the right plane to catch the emissions.
Well, if 3.7 billion is close, then I'd hate to contemplate what would happen if that nearby unstable monster Betelgeuse or similar were to collapse. It's only about 600ly away. And the supergiant VY Canis Majoris is just 4000ly or so. Such distances are ridiculously small compared to 3.7 billion.
For Betelgeuse, very little. It's rotational axis is away from Earth, so a GRB won't hit us.
It *would* be brighter than the full moon and visible during daylight.
However, its shell would eventually reach our solar system, collapsing the solar magnetopause, possibly to Earth.
That would render space travel pretty much impossible.
That said, the shell of protons and assorted other particles wouldn't reach the solar system until around 100000 years after the supernova.
As for VY Canis Majoris, too far away to do anything to us beyond giving a nice show.
And perhaps, fracture some more theories. ;)
Was aware axis of Betelgeuse would mean little harm to us, it was the only one I could think of that was very large, reasonably close and somewhat unstable w/o doing a search. However a while ago I read a report stating that if a star the size of Betelgeuse were collapse at ~300ly then we'd be in quite some strife even if off axis.
VY Canis Majoris, again because it came to mind as comparatively close and extremely large--the point here was the wording of the article:
Had the GRB 130427A event happened in our own galaxy then Earth may have been very seriously affected, possibly to the level of it being an extinction event for humanity.
As our galaxy is ~100k x ~20kly--with no distances being mentioned--then VY C/M at 4kly was 'comparatively close' (all trivial compared to 3.7 billion).
Got some better examples?
Shouldn't the hope be that Betelgeuse or any other star hasn't already imploded? For such an event to affect life on Earth (in our lifetime or that of our near descendants), it would have had to occur many millions, if not billions, of years ago. I get lost thinking through the implications of time perspective. Star gazing is like looking at a record of how things appeared across billions of years, not now.
"We normally detect GRBs at great distance, meaning they usually appear quite faint," study co-author Paul O'Brien, an astronomer at the University of Leicester in the United Kingdom, said in a statement. "In this case, the burst happened only a quarter of the way across the universe — meaning it was very bright."
Thanks Universe, for reminding me how insignificant we are at regular intervals.
Black holes are theorised to create gamma rays because gravity is so weak. Electromagnetic forces, on the other hand, are 10^39 times stronger. Lightning produces gamma rays, so a big cosmic lightning bolt would have no problems producing high-energy cosmic rays, and you don't need the black hole.
err, wouldn't the required magnetic fields and voltage be _very_ large ? Even by cosmological standards? So large they would go off long before a 20 hour stroke could be generated ? Are you suggesting a new magnetar hitting carbon dust ? Not a reader of "The Sun is Iron" are we ?
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"Electric and magnetic fields are much better at producing gamma rays, as is demonstrated by lightning bolts, from which gamma rays have been detected."
OK, why don't you hang out over the rotational pole of Sag A* and tell us all about it when that gas cloud hits in a few years.
Back on 19911015, a detector in the USA detected a cosmic ray particle (probably a proton, known as the Oh My God particle) with an energy of 3E8 TeV (about the same as a baseball thrown at 55 mph).
Bert and Ernie come in at about 1E3 TeV in energy. A proton has a mass of about 938 MeV, and a neutrino has a mass of about 0.23 eV.. The mass of a proton is about 4E9 more than the mass of a neutrino.
What ever gave rise to Bert and Ernie, was a much more energetic event than gave rise to the Oh My God particle. At least in my humble understanding as a materials scientist.
If the gamma flux in significant it doesn't matter that only one hemisphere of the Earth is exposed.
The danger is not radiation sickness. It's bulk ionisation of the atmosphere. Break down a significant percentage of the oxygen and nitrogen molecules, and they'll recombine into Nitrogen Oxides by the megatonne. Cue (a) instant destruction of the ozone layer and (b) decades of Nitric Acid rain.
Land life is the most vulnerable to these. The oceans are a very large sink, so life in the deep ocean has the best chance.
It's not very likely, though it fits the fossil pattern of one of the mass extinctions as well as anything else. One thing for sure, we wouldn't see it coming.
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